Impacts of food contact chemicals on human health
Research on Chemical Intermediates publishes current research articles and concise dynamic reviews on the properties, structures and reactivities of intermediate species in all the various domains of chemistry.

The journal also contains articles in related disciplines such as spectroscopy, molecular biology and biochemistry, atmospheric and environmental sciences, catalysis, photochemistry and photophysics. In addition, special issues dedicated to specific topics in the field are regularly published. 

Food packaging is of high societal value because it conserves and protects food, makes food transportable and conveys information to consumers. It is also relevant for marketing, which is of economic significance. Other types of food contact articles, such as storage containers, processing equipment and filling lines, are also important for food production and food supply. Food contact articles are made up of one or multiple different food contact materials and consist of APIs and Intermediates. However, food contact chemicals transfer from all types of food contact materials and articles into food and, consequently, are taken up by humans. Here we highlight topics of concern based on scientific findings showing that food contact materials and articles are a relevant exposure pathway for known hazardous substances as well as for a plethora of toxicologically uncharacterized chemicals, both intentionally and non-intentionally added. We describe areas of certainty, like the fact that chemicals migrate from food contact articles into food, and uncertainty, for example unidentified chemicals migrating into food. Current safety assessment of food contact chemicals is ineffective at protecting human health. In addition, society is striving for waste reduction with a focus on food packaging. As a result, solutions are being developed toward reuse, recycling or alternative (non-plastic) materials. However, the critical aspect of chemical safety is often ignored. Developing solutions for improving the safety of food contact chemicals and for tackling the circular economy must include current scientific knowledge. This cannot be done in isolation but must include all relevant experts and stakeholders. Therefore, we provide an overview of areas of concern and related activities that will improve the safety of food contact articles and support a circular economy. Our aim is to initiate a broader discussion involving scientists with relevant expertise but not currently working on food contact materials, and decision makers and influencers addressing single-use food packaging due to environmental concerns. Ultimately, we aim to support science-based decision making in the interest of improving public health. Notably, reducing exposure to hazardous food contact chemicals contributes to the prevention of associated chronic diseases in the human population.

We, as scientists working on developmental biology, endocrinology, epidemiology, toxicology, and environmental and public health, are concerned that public health is currently insufficiently protected from harmful exposures to food contact chemicals (FCCs). Importantly, exposures to harmful FCCs are avoidable. Therefore, we consider it our responsibility to bring this issue to the attention of fellow scientists with relevant expertise, but currently not engaged in the area of FCMs, as well as decision makers and influencers in government, industry and civil society dealing with environmental and health-related aspects of food packaging. We propose that a broader, multi-stakeholder dialogue is initiated on this topic and that the issue of chemical safety of food packaging becomes a central aspect in the discussions on sustainable packaging.

Food contact chemicals (FCCs) are the chemical constituents of food contact materials and finished food contact articles, including food packaging, food storage containers, food processing equipment, and kitchen- and tableware [1, 2]. We define FCCs as all the chemical species present in food contact articles, regardless of whether they are intentionally added or present for other reasons.

It is clearly established by empirical data that FCCs can migrate from food contact materials and articles into food, indicating a high probability that a large majority of the human population is exposed to some or many of coenzymes and nucleotides series [3]. Indeed, for some FCCs there is evidence for human exposure from biomonitoring [4,5,6,7,8,9,10,11], although some FCCs may have multiple uses and also non-food contact exposure pathways.

When food contact material regulations were first developed, it had been generally assumed that low-level chemical exposures, i.e. exposures below the toxicologically established no-effect level, pose negligible risks to consumers, except for carcinogens [12, 13]. However, more recent scientific information demonstrates that this assumption is not generally valid, with the available evidence showing that exposure to low levels of endocrine disrupting chemicals can contribute to adverse health effects [14,15,16,17,18,19,20]. In addition, chemical mixtures can play a role in the development of adverse effects [21,22,23,24], and human exposure to chemical mixtures is the norm but currently not considered when assessing health impacts of FCCs [1]. The timing of exposures during fetal and child development is another critical aspect for understanding development of chronic disease [25]. Currently, these new and important insights are still insufficiently considered in the risk assessment of chemicals in general, and of FCCs in particular [20]. We have previously published an in-depth analysis of the scientific shortcomings of the current chemical risk assessment for food contact materials in Europe and the US [1]. For example, in the European Union (EU) the regulation EU 10/2011 includes a list of authorized substances for the manufacture of plastic materials and articles in contact with food and, for some of the fine chemicals, their permitted maximum concentration, either in the plastic food contact article or in food (i.e. specific migration limit) [26]. However, there are still many substances that are present in plastics and other materials as non-intentionally added substances (NIAS). Even though the EU regulations 10/2011 explicitly and EU 1935/2004 generally require a risk assessment of NIAS, there are many difficulties: first, identification of NIAS is very demanding [27] and, secondly, studying the effects on human health is often not possible because for example the chemicals are not available as pure substances or testing would be too expensive [1]. What is more, there is no regulatory requirement to assess toxic effects of the chemical mixtures migrating from food contact articles [1]. To summarize, we are concerned that current chemical risk assessment for food contact chemicals does not sufficiently protect public health.

Therefore, we would like to bring the following statement to the attention of policy makers and stakeholders, especially those currently working on the issue of packaging waste but not focusing on the chemical safety of food contact articles (Table 1). By mapping the challenges (Table 2), we aim to initiate a broader debate that also involves scientists with different expertise of relevance to the issue. Importantly, chemical safety must be addressed in two ways: e.g. (i) a discussion of how chemical safety is ensured, based on the current scientific understanding and e.g. (ii) a debate of the chemical safety of food packaging in the circular economy, which aims at minimizing waste, energy and resources use [28]. Therefore, we provide an overview of the most pressing challenges based on current scientific understanding. Ultimately, the public is to be protected from exposures to hazardous FCCs while at the same time the aims of the circular economy need to be achieved. To reach these goals, we think that there is a need to better inform decision making on future food packaging research and policy.
Chemicals can transfer from food contact materials and articles into food. This phenomenon is known as migration and has been studied since the 1950s [29,30,31,32,33]. All types of food contact materials may exhibit chemical migration, but the types of migrating Sitagliptin Phosphate Monohydrate CAS 654671-77-9 and their levels differ significantly. 

Analysis of FCC lists issued by legislatures, industry, and NGOs worldwide indicates that almost 12,000 distinct chemicals may be used in the manufacture of food contact materials and articles [67]. For example, European Union (EU) and EU Member State regulations list a total of 8030 substances for use in different types of food contact articles [68]. In the United States (US), 10,787 substances are allowed as direct or indirect food additives, and roughly half of these are FCCs [69]. Many additional FCCs may be used in the US under the assumption of being generally recognized as safe (GRAS), but they are not notified to the US Food and Drug Administration (FDA) and therefore no public record on their use is available [70]. In general, information on the actual use of a chemical in food contact materials (and its levels) is difficult to obtain [71, 72].

All migrating FCCs have inherent toxicity properties that can cause different effects at different doses and are related to the timing of exposure, mode of action, and other aspects. At the same time, levels of FCCs that humans are exposed to reflect their use (or presence) in a food contact article and are associated with its concentration in food. To evaluate the risk of a given chemical to human health, information on its inherent toxicity (i.e., its hazard) and the actual levels of exposure is needed.
Many of the chemicals that are intentionally used in the manufacture of food contact articles have not been tested for hazard properties at all, or the available toxicity data are limited [67]. Moreover, endocrine disruption, as a specific hazard of concern, is not routinely assessed for 2,4,5-Trifluorophenyl Acetic Acid CAS 209995-38-0 migrating from food contact articles, although some chemical migrants are known endocrine disruptors [73,74,75,76,77].

Exposure data are commonly based on assumptions or estimates – for example derived from dietary assessments or unpublished (proprietary) data of an intentionally used FCC’s concentration in a food contact article [71, 78, 79]. Thus, there is significant uncertainty associated with these data. In short, decisions on the use of a chemical in food contact materials are commonly made in data-poor situations.

Christmas crafts for adults to try this festive season
Christmas crafting is one of the best ways to spend Christmas 2021. Pick a project from our easy, step-by-step guides to start making fabulous Christmas arts and crafts, decorations and handmade Christmas gifts that your friends and family will love. 

Christmas is here, so shops are reeling us in with their Christmas adverts, sparkling lights and ornate, festive displays. Despite the fact we can all enjoy a spot of Christmas shopping, nothing sums up the spirit of the season more than lovingly-gifted handmade gifts, decorations and treats.

Not only is embarking on a daily craft decorations project a cosy way to spend a winter evening; handmade Christmas gifts are also a more sustainable way to tell your friends and family you love them and to decorate your home as the festivities get underway. 

After last year’s damp squib of a festive season, handmade gifts are also a heartfelt and meaningful way to tell your friends and family how much they mean to you as we’re (hopefully) reunited this Christmas.

Whether you’re looking to craft your own Christmas wreath, make your own Christmas candles to place on a sparkling Christmas table or make personal, handmade gifts for your loved ones, there are plenty of Christmas arts and crafts to keep you busy this festive season.  

Take a look at our list of daily use decorations ideas you can easily try your hand at – from decorations for your home and Christmas food and drinks to fun gift ideas. Rest assured, you won’t be making any old stocking fillers. All our guides will show you how to make trending and useful crafts, from stylish dried flower wreaths and Instagram-approved painted candles to collaged Christmas cards and festive sloe berry gin.

Whether you’re a crafting fanatic looking for new ideas or a beginner searching for easy to make arts and crafts that will still look slick and professional, you’ve come to the right place. Merry Christmas and happy crafting.

Give a truly heartfelt Christmas present this year by making your very own gifts by hand. Not only will your loved ones appreciate them so much more, it also means you can make your presents as eco-friendly as possible (there’ll be no excess cardboard or shrink-wrap on these bespoke gifts). 

Whether you want to make traditional festive favourites to spread some cheer this season, or you’d prefer to home craft decoration fun items that your friends and family will be able to keep forever, there’s a craft on our list for you. 

Christmas is a time to wine and dine. But, instead of automatically going to the supermarket for all your culinary needs, why not try making your favourite festive snack and treats instead. Handmade food and drink is also a great gift idea. 

From festive tipples to foodie gifts that your friends and family will be able to use all year round, these easy how-to guides will keep you busy this Christmas. 

Christmas means decking your halls with soft twinkling lights and bright, colourful decorations. Whether you’re looking to level up your Christmas tablescaping game this year with handmade candles and lovingly crafted placemats or you’re after some stunning floral arrangements to bring the festive vibes, there’s a crafting guide here for you. 

With winter break upon us and Christmas just around the corner, it’s time to embrace the festive spirit of the season. Escape the chilly weather by staying indoors and crafting with your kids. Christmas crafts are a great way to entertain your little ones while letting them release their creativity.

We have 50 easy Christmas crafts for kids at every skill level. Need to decorate your Christmas tree? There are fun Christmas tree ornament ideas that your kids will be excited to hang up. Looking for a personalized Christmas gift you can give to family? Try creating a snow globe or themed treat.

Once you decide on a craft to make, pair it with light up Christmas decorations to give your home the complete cozy Christmas feel.

The festive season is the perfect time for some do-it-yourself fun with the kids, who love cutting paper and using glue to create magical shapes. Get creative making stars, ornaments to decorate the tree. Children will get a sense of pride and achievement seeing the handmade decorations on the festive tree. Here, we show how you can make a paper tree and decorations.

Make cones out of all the papers. You will require about six to seven sheets of each colour. Now, stick the cones together, starting from the bottom with the largest cone and ending with the smallest on top. After sticking all the cones now make a star and stick it. You can attach a ribbon, so that you can use it to hang on the tree.

From making your fireplace more festive to crafting one-of-a-kind ornaments and trimming your Christmas craft decorations, our holiday craft projects will help you creatively take your home from ho-hum to ho-ho-ho! Get crafting to deck out every area with DIY Christmas decorations that perfectly showcase your personal seasonal style.

For many, it (wrongly) contained connotations of amateurism, appearing homespun and deeply unfashionable.

Scroll forward to the present and things look very different. Tom Daley made headlines at the Olympics, not only for winning medals but also for knitting a commemorative cardigan while supporting Team GB in the stands.

Our TV schedules are overrun with shows devoted to sewing, repair, pottery and jewellery making. And brands from Loewe to Kettle Chips have celebrated craft (with different degrees of credibility) through awards and marketing campaigns.

What changed? I would posit that the craft revival started in 2008, with the combination of the banking crisis and the publication of a hugely influential book, The Craftsman by Richard Sennett. Historically, craft does well in recession, when people pay more attention to the value of things and are more willing to entertain the idea of repairing possessions rather than simply binning them.

So the field of craft has garnered some (long-overdue) kudos. But what’s next? And who are the people taking it forward?

According to Annie Warburton, CEO of Cockpit Arts, London’s leading studios for contemporary crafts, ‘Craft is advancing on several different fronts.’ And one of those fronts is the collectibles market. Last year, for instance, studio ceramics auction house Maak sold a piece by Magdalene Odundo for £240,000, a record for a living ceramic artist.
In June, Design Centre Chelsea Harbour launched Artefact, a new fair devoted to high-end craft, while craft galleries such as Adrian Sassoon and Sarah Myerscough have become staples at international art and design shows like Masterpiece and PAD. As Warburton points out, compared to the fine art world, there are potential bargains to be had: ‘People are realising that, at the moment, the field is seriously undervalued in terms of price. Canny collectors are getting in on collectable craft.’

Makers themselves are also expanding craft’s horizons through a combination of technology and material experimentation.

Gareth Neal is a designer and maker, whose work in wood has ranged from investigating the traditional Orkney chair to working with cutting-edge CNC (computer numerical control) processes to create ‘Ves-el’ vases, in collaboration with the late Zaha Hadid. Most recently, he has been experimenting with 3D-printing sand (in a process called binder jetting) to create a huge, ribbed vessel that’s a little under two-metres tall.

‘I see technology as another tool,’ he says. ‘It’s just that nowadays tools are no longer something you carry about in a box on the back of a cart. They’ve outgrown the traditional workshop.’ Interestingly, Neal shies away from describing himself as a craftsman preferring the term, ‘craft explorer’. ‘I’m someone who is trying to find new territory and uncover different areas to play in,’ he says.

While Neal is using technology to challenge established notions of craft, James Shaw is fascinated by how we place value on materials. He has eschewed current fashion and has become an advocate for plastic.

‘I was quite interested in the hierarchy of materials, where plastic comes way down at the bottom,’ he explains. ‘I thought maybe there was some connection between that and the silly things we do with it, like using it for a few seconds and throwing it away. I figured if I applied the skills, understanding and time that easter craft decorations, it might unpack some other aspects of the material.’

For his ‘Plastic Baroque’ series, Shaw takes high-density polyethylene pellets (recycled from packaging), which are heated, extruded through a kind of homemade gun, and then rapidly manipulated before the gooey substance cools down, to create objects that are subsequently sold on the collectibles market.

He is by no means alone in working with materials more often thought of as waste. Emma Witter is a maker and artist who uses animal bone to create wonderfully delicate sculptures. She began working with the material for practical reasons.

‘It was about having no money and working with what was around me,’ she explains. ‘If I wanted to use metal, for example, I’d have to go to a foundry, which is expensive. So I was collecting things that were to hand and free.’ She picked up her first bones from her own meals and at dinner parties. ‘On the odd occasion we went to restaurants, I’d put them aside,’ she tells me, with a hint of a giggle.



Importantly, too, there has been a collective realisation in the craft world that it needs to expand its base and appeal to a more diverse cross-section of the population.

Over the past 18 months, for example, it has been fascinating to watch the rise of Chris Day, a mixed-heritage glass artist, who graduated from Wolverhampton University in 2019. Since then, his extraordinary work, which focuses on the Black experience in the UK and US, juxtaposing glass and copper piping and wire, has been shown at London’s SoShiro and Vessel Gallery. He currently has a genuinely moving installation at All Saints Church at Harewood House, just outside Leeds.

The beauty of craft is that it is light on its feet. Makers are playing with new techniques and materials that could inform all our futures. And it has something to say on a range of topics, too, from sustainability to discrimination.

In short, craft is not to be underestimated.

Choosing Pots and Pans to Improve Your Cooking
As a Fine Cooking editor, I’ve had the chance to observe lots of great cooks at work. From them, I’ve learned plenty—including the fact that good-quality pots and pans made of the right materials really can improve your cooking.

Rather than having a rack filled with stock pot and pans of all shapes and sizes, owning a few well-chosen pieces will give you the flexibility to cook whatever you want and the performance you need to cook it better.

I polled some of our authors to find out which pans were the most valuable to them and why. I then came up with six pieces, starting with two indispensables: an anodized-aluminum stockpot to handle stocks, soups, stews, some sauces, blanching, boiling, and steaming; and a high-sided stainless-steel/aluminum sauce pan with a lid for frying, deglazing sauces, braising small items like vegetables, making sautés and fricassées, cooking rice pilafs and risottos, and a whole lot more. The other four pieces I picked make for even more cooking agility and add up to half a dozen ready-for-action pots and pans that you’ll really use (see For every pot, there’s a purpose…).

All good pans share common traits
In a well-stocked kitchen store, you’ll see lots of first-rate pots and deep fry pan. They may look different, but they all share essential qualities you should look for.

Look for heavy-gauge materials. Thinner-gauge materials spread and hold heat unevenly, and their bottoms are more likely to dent and warp. This means that food can scorch. Absolutely flat bottoms are particularly important if your stovetop element is electric. Heavy-gauge pans deliver heat more evenly (see “Good pans are worth their price…,” below).

To decide if a pan is heavy enough, lift it, look at the thickness of the walls and base, and rap it with your knuckles—do you hear a light ping or a dull thud? A thud is good in this case.

Good pans are worth their price because they manage heat better
“Good conductor” and “heavy gauge” are the key features of good cookware. Here’s how these characteristics affect cooking.

You get responsive heat. Good heat conductors, such as copper and aluminum, are responsive to temperature changes. They’ll do what the heat source tells them to do—heat up, cool down—almost instantly.

You get fast heat flow. Heat flows more easily through a good heat conductor, assuring a quick equalizing of temperature on the cooking surface.

You get even heat diffusion. A thicker pan has more distance between the cooking surface and the heat source. By the time the heat flows to the cooking surface, it will have spread out evenly, because heat diffuses as it flows.

You get more heat. Mass holds heat (heat is vibrating mass, so the more mass there is to vibrate, the more heat there will be). The more grill pan there is to heat, the more heat the pan can hold, so there’s more constant heat for better browning, faster reducing, and hotter frying.

You’ll want handles and a lid that are sturdy, heatproof, and secure. Handles come welded, riveted, or screwed. Some cooks advise against welded handles because they can break off. But Gayle Novacek, cookware buyer for Sur La Table, has seen few such cases. As long as handles are welded in several spots, they can be preferable to riveted ones because residue is apt to collect around a rivet.

Many pans have metal handles that stay relatively cool when the pan is on the stove because the handle is made of a metal that’s a poor heat conductor and retainer, such as stainless steel. Plastic and wooden handles stay cool, too, but they’re not ovenproof. Heat- or ovenproof handles mean that dishes started on the stovetop can be finished in the oven.

All lids should fit tightly to keep in moisture. The lid, too, should have a heatproof handle. Glass lids, which you’ll find on certain brands, are usually ovensafe only up to 350°F.

A pan should feel comfortable. “When you’re at the store, pantomime the way you’d use a pot or pan to find out if it’s right for you,” advises Fine Cooking contributing editor and chef Molly Stevens. If you find a pan you love but you aren’t completely comfortable with the handle, you can buy a rubber gripper to slip over the handle. Just remember that grippers aren’t ovenproof.

Some pans need special talents
Depending on what you’ll be cooking in the pan, you may also need to look for other attributes.

For sautéing and other cooking that calls for quick temperature changes, a pan should be responsive. This means that the fry pan is doing what the heat source tells it to, and pronto. For example, if you sauté garlic just until fragrant and then turn down the flame, the pan should cool down quickly so the garlic doesn’t burn. Responsiveness isn’t as crucial for boiling, steaming, or the long, slow cooking that stocks and stews undergo.

For sautéing and oven roasts, it helps if the pan heats evenly up the sides. When you’ve got a pan full of chicken breasts nestling against the pan sides, you want them all to cook quickly and evenly, so heat coming from the sides of the pan is important. Even heat up the sides of a pot is important for pot roasting, too. Paul Bertolli, Fine Cooking contributing editor and chef of Oliveto restaurant in Oakland, California, counts on his enameled cast-iron oval casserole by Le Creuset for braising meat because “it’s a snug, closed cooking chamber with even heat radiating off the sides for really good browning.” Bertolli finds that meat fits especially well into the oval shape.

For cooking acidic foods, such as tomato sauces, wine sauces, and fruit fillings, a pan’s lining should be nonreactive. Stainless steel, enamel, and anodized aluminum won’t react no matter what they touch, while plain aluminum can discolor white sauces and foods that are acidic, sulfurous, or alkaline. It can even make those foods taste metallic. Eggs, vegetables in the cabbage family, and baking soda are some of the other foods vulnerable to aluminum’s graying effect. In the past, there was concern about aluminum and Alzheimer’s, but evidence has been far from conclusive.

Interview yourself to help you choose the right pans
There’s nothing wrong with matching cookware in principle. Packaged starter sets are attractively priced, and a whole lineup of matching pans can be attractive, too. But a single material isn’t suited for every kitchen task—with sets, you’re often stuck with pans you don’t need. That enameled cast-iron casserole is just right for the cassoulet you’ll move from stovetop to oven. But its matching saucepan overcooked your last caramel because the pan was too heavy to heft quickly once the sugar turned color.

You’ll get more use out of pieces that you hand-pick yourself. You may already own a matched set (the red Le Creuset ensemble I got years ago as a housewarming present is still hanging in my kitchen), but as you add new pieces to your collection, you’ll have a chance to branch out to different materials (see “Materials that make the pot”).

To decide what you need, ask yourself questions like the ones that follow.

Materials that make the pot
The letters identifying the materials key to the photo below.

A. Stainless steel is a poor conductor of heat all by itself, but it’s a peerless surface metal: easy to clean, durable, shiny for good visibility, and completely nonreactive.

B. Copper is a superb heat conductor and radiates visual warmth, too, if you keep it polished. All alone, copper is highly reactive with food, so the pans must be lined. It’s often used as a bottom layer for better heat conduction.

C. Aluminum is a top-notch heat conductor and is lightweight and easy to handle, but it reacts with acidic, sulfurous, and alkaline foods. Aluminum is often used as a core or bottom layer for better heat conduction.

D. Cast iron is an excellent retainer of heat and great for high temperatures. It’s relatively slow to heat up and cool down, and needs thorough drying and oiling.

E. Nonstick coatings have greatly improved to withstand high heat and abrasion.

F. Anodized aluminum is aluminum that’s been electrochemically sealed, making for a nonreactive, hard surface. The dark interior, though, makes it difficult to see color change in pan juices and translucent sauces.

G. Enameled cast iron’s coating solves the maintenance problems of cast iron, but the heating benefits remain. The enamel coating can chip with wear and abrasion.

Are you more likely to make saucy dishes like fricassées and sautés than delicate foods like omelets and crêpes? A bigger sauté or frying pan with high sides and a lid may be a better choice than a shallower, slope-sided omelet pan without one. “At home, I make a lot of dishes where the pasta gets thrown in with the other ingredients for the last few minutes, and my anodized-aluminum sauté pan is the one I always grab,” says Molly Stevens of her favorite Calphalon pan. “It’s responsive, I know the food won’t scorch, and I love the handle.” She adds that its anodized surface is easy to clean.

Do you cook lots of soup on weekends to freeze for meals during the week? A heavy stockpot may be essential. “I always choose heavy-gauge for anything that stays on the stove a long time,” says Larry Forgione, chef/owner of the New York City restaurant An American Place, who says food burns and sticks whenever he uses a thin stockpot. Abby Dodge, Fine Cooking’s recipe tester, agrees. “With soups and stocks, a heavy bottom comes first,” she insists. “And if your budget allows it, go for the best.”

Do you make pasta several times a week? Don’t toss that big, thinner-gauge pasta pot if you already have one; it’s fine for boiling and steaming — and lighter is better when you’re carting a boiling pot from stove to sink. But if you don’t have a big pot yet, think about doubling up your pasta-boiling with stock- and soup-making by using a heavy stockpot.

Do you like making sauces? “When I’m browning or deglazing, I need to see what the pan juices are doing,” says Jim Peterson, Fine Cooking contributing editor and chef. For such jobs, he avoids pans with a darker interior, such as anodized aluminum, and prefers a shiny stainless-steel lining.

Nancy Silverton, baker, pastry chef, and co-owner of La Brea Bakery and Campanile in Los Angeles, agrees. “I love the steady heat and surface of seasoned cast iron, but seeing color change is crucial, so I need a pan that’s bright inside, like stainless,” she says. Silverton cautions that tin- and aluminum-lined pans affect the taste of acidic foods, such as compotes and fruit fillings. Both Peterson and Silverton love the visual warmth of copper but agree that top-notch stainless with an aluminum core, like All-Clad, works just as well.

Do you often serve stews, pot roasts, or braised meat dishes? Paul Bertolli loves the way Le Creuset enameled cast iron handles such dishes. “I can start dishes on the stove, transfer them to the oven, and all the juices will be ready to deglaze in the same pot.” He adds that one-pot cooking makes for swift cleanup, too. And Scott Peacock, a southern chef, loves enameled cast iron because “you can put on a lid, set the pot at the back of the stove, and it will hold the food at a good serving temperature a long while.”

Do you like cooking chops, steaks, or thick fish fillets? Cast iron may be heavy, but chef and writer Regina Schrambling says that “for searing fish at intense heat and finishing it in the oven, I trust it.” Scott Peacock likes it, too, especially for making golden-crusted cornbread, but cautions that unless cast iron is well seasoned, it can make acidic foods taste metallic, and that metal utensils themselves are apt to scrape off seasoning.

Are you trying to cook with less fat? Nonstick may be a good choice, and happily, nonstick technology has come a long way in the past few years. With the old-style, lighter-weight nonstick pans, it was hard to get the pan hot enough to sauté properly. Nonstick pans are now being made of harder, high-heat-tolerant metals, such as anodized aluminum and stainless steel, and the coatings themselves can withstand more heat and abrasion — no more nonstick flakes in your food. Another potential disadvantage of sautéing in nonstick is the difficulty in deglazing. The nonstick surface can be so effective that you never get any good brown bits in the bottom of the pan. With Circulon, which has a finely ridged nonstick interior, browning takes place more like in a conventional pan, and Circulon’s Commercial line is super heavy duty.

The Chinese iron pan can function as a nonstick pan even without a polytetrafluoroethylene (PTFE) coating after a “Kitchen God blessing” seasoning process. We simulate this process and disclose the science behind the “Kitchen God blessing,” finding that through repeated oil-coating and heating, the reversible insertion and extraction of oxygen atoms split the surface of the iron pan, gradually producing Fe3O4 nanoballs. These balls give the iron pan a conditional hydrophobicity property, meaning the pan would be hydrophilic when the ingredients contain much water and hydrophobic when they contain less water. The former enables heat to be transferred rapidly through the nanoballs while the latter slows down the heat transference and prevents the pan from sticking. This discovery provides an approach of generating nanoballs on the surface of the metal and also discloses the secret of the fantastic taste produced by cooking with a Chinese iron pan.

“Kung-Pao Chicken,” one of the most famous Chinese dishes, is difficult to cook in Western kitchens. The secret behind the successful creation of this dish is the Chinese iron pan. Nonstick pans are produced by coating them with polytetrafluoroethylene (PTFE) materials to construct a superhydrophobic surface [1,2]. Besides the environmental and safe concerns about the PTFE coating, the PTFE's low surface energy [3,4], although it creates a nonstick pan, is detrimental to the taste of the cooked food. Because of the oleophobic/hydrophobic quality of the PTFE materials, the fat serving as the heating medium aggregates into clusters instead of dispersing homogeneously, hindering the even transference of heat to the ingredients, adversely affecting the taste of the final product. In contradistinction to this, there is an ancient saying in China that the Kitchen God will bless a pan and endow it with the oleophilic/hydrophobic quality and a stainless surface after a special seasoning process. The seasoning process, or “the pan's inauguration”, is somewhat religious in nature, but the result, in actuality, is based on science. At the very beginning, the Kitchen God, a native Chinese spirit, is invited through incense-burning. Then, the inner surface of a fresh pan is coated with animal fat (in this work we chose beef tallow). Next, the pan is placed on a stovetop and heated with a low flame for several minutes. This process is repeated several times until the Kitchen God's blessing is received. After seasoning, the pan, made of cast iron, will remain bright for several years. In reality, seasoning ends when the pan has made the proper contact angles with the water and oil, which is determined by the chef, rather than by the Kitchen God (Fig. 1(a, b and c)). The oil acts as the reaction medium in the cooking process, making an oleophilic surface essential for the food to have a good taste. Ingredients are always watery, so a hydrophobic surface is vital for a nonstick pan. For this reason, almost every chef in a Chinese restaurant treats their oleophilic/hydrophobic iron pans as priceless treasures. As they generally don't know how to season their pans properly, most Westerners find it difficult to replicate the taste of Kung-Pao Chicken or other delicious stir-fried Chinese food.

Now the secret behind the seasoning of the Chinese iron pan will be revealed. We investigated the seasoning process with burner temperatures ranging from 375○C to 600○C. The morphologies of these experiments are shown in Fig. 2(a). The samples were named Fe-temperature-cycle number, e.g., Fe-450-3 refers to the sample seasoned three times at 450○C. The surface of the pan turned black after seasoning at 375○C and 450○C and rusted at 600○C. As shown in Fig. 1(b), after five cycles of seasoning at different temperatures, Fe-450-5 exhibited a hydrophobic surface with a contact angle of 117.6○ with water droplets. All the samples had oleophilic surfaces, which guarantee uniform heat transfer from the pan to the food (Fig. 1©). The hydrophobicity of the Fe-450-5 surface was attributed to the formation of Fe3O4 nanoballs after seasoning.

The volume expansion during the seasoning cycles is reversible. The diagrams and SEM images in Fig. 3(d–e) show the vertical formation and growth of Fe3O4 nanoballs. We can clearly determine that when an iron pan is seasoned at 450 °C, the smooth surface of the iron pan gradually becomes coarse during the first two cycles, and nanoballs begin to appear. Interestingly, the nanoballs shrink after the 3rd seasoning cycle (Fig. 3(d) and Fig. S2). For each seasoning cycle, the beef tallow first provides a low Po2 and then evaporates to provide a high Po2. During this process, the coordinate number of the surface iron atoms repeatedly changes between six and four. The formed Fe3O4 repeatedly shrinks and expands and finally large particles crack into small nanoballs.

The Safe Use of Extension Cords in the Lab
Essential to modern life and a familiar part of our surroundings, yet often not treated with deserved respect. Run over, walked on, crimped in windows and doors, left out in sun and storm alike, strung together, bent, yanked, and strung across rooms and under carpets, strewn across wet grass and through holes in walls, taped up and snarled in tangles that would give a sailor nightmares. Used in the office, in the lab, and in the field, taken for granted until you need one. What are we talking about? American UL power cords, one of the most indispensable tools we use today, but too often with little consideration. And, sometimes used in a fashion that could have disastrous results.

In 1997, more than 12,000 people were treated for electrical shocks and burns; about 2,500 of them were treated for injuries stemming from extension cords.1 In addition, each year about 4,000 injuries associated with electric extension cords are treated in hospital emergency rooms. Half of these injuries involve fractures, lacerations, contusions, or sprains from people tripping over extension cords. Roughly 3,300 home fires originate in extension cords each year, killing 50 people and injuring about 270 more.2 However, with a little care and some precautions, these conveyors of power can be used safely.


We must caution up front, that if you have more than a few Europe VDE Power Cords powering equipment in your lab, it is probably time to either call an electrician to install additional strategically placed outlets, or to rearrange equipment. Likewise, if you have any cords running through walls, up through the ceiling and down somewhere else, an electrician is definitely required. Extension cords should only be used when necessary and only for temporary use. You should always plug equipment directly into a permanent outlet when possible. Where this is not possible, however, you should begin by selecting the right cord for the job.

Indoors or outdoors, the use of extension cords serve different needs and should be selected accordingly. Regardless of location, always use the three-prong type of cord approved for either indoor or outdoor use. In addition, the cord should have a certification label from an independent testing lab such as UL (Underwriters Laboratories) or ETL (Electrical Testing Laboratories) on the package and attached to the cord near the plug.

The amount of current a cord can handle will depend on the diameter of the conductors (copper wire part of the cord). Cords that contain more copper can safely handle more power. The wire size is measured by the gauge of the wire. You will usually find numbers like 16, 14, or 12 gauge on an extension cord package and the cord itself. Now, this is one of those confusing issues. You would think that a 16-gauge wire is bigger than a 12-gauge wire, but it’s not! As the number gets smaller, the thickness of the conductor gets bigger. A 12-gauge wire can safely carry much more power than a 16-gauge wire. Compare the capacity on the label to the intended load.

Always use the shortest extension cord possible, to minimize risk of damage to the cord and reduce electrical resistance across the length of the cord. Extension cords, by the nature of their length and conditions of use, are much more prone to damage than other types of wiring. It is important to check the total length of the cord for damage before putting it into use.

One should start by looking at the ends of the cords. The male end—the end with the three prongs that fit into an electrical outlet—is the one that is most prone to damage. The two flat power-conducting prongs are subject to bending, while the round prong (often called the ground pin), can be broken off. Without the ground pin there is no path to ground through the wires—potentially a very dangerous situation.

Outdoor use extension cords, and many equipment cords, have a tough outer layer designed to protect the inner wires. If the outer jacket is damaged, the softer inner insulation around the wires can easily become damaged as well. Does this mean you should whip out the tape to repair it? No, damage to an extension cord jacket, or any cord for that matter, should never be fixed by wrapping it with tape. Even electrical tape does not have sufficient strength or abrasion resistance to make a permanent repair as required by OSHA. A taped-up extension or power cord to a piece of equipment is an easy OSHA citation.

So, what to do if you have a damaged cord? If the damage is extensive, cut off the plug and throw it out. Replace it with a new cord. Alternatively, the cord can be cut at the point of damage and a new plug installed. Too many times, especially if the female end is damaged, we see outlet boxes intended for structural use installed on the extension cord. These are not permitted if the box is designed to be surface mounted. The clues to easy identification are indentations (knockouts) on the side about the size of a nickel and small holes on the back. Instead, use hard-walled outlet boxes that are approved for use on a flexible cord.


Next, where to plug it in? If you are outside, or in a wet or damp location, or near water, look for outlets protected by Ground Fault Circuit Interrupters (GFCIs). A GFCI is a fast-acting device that detects small current leakage from electrical equipment. In other words, it senses electricity traveling to ground via something other than the wires, such as yourself. It shuts off the electricity within 1/40th of a second if sufficient current leakage is detected. It provides effective protection against shocks and electrocution. GFCI pigtails—very short cords with a GFCI built in—can be used with plug and cord equipment in areas without protected outlets. Although GFCI outlets are required by building codes for bathrooms, kitchens, rooftops, and garages, they are not always required near laboratory sinks. This requirement varies by locale and code enforcement authority. We think, however, it is a good idea, and almost always recommend them on outlets within six feet of laboratory sinks.

Special cases, such as in pits, tanks, or near certain manufacturing processes where flammable materials are used, require special electrical equipment designed such that they will not be possible ignition sources. This equipment carries the designation “intrinsically safe.” Only intrinsically safe equipment may be used in these potentially explosive areas.


A tertiary care 1000 bedded hospital contains more than 10,000 pieces of equipment worth approximately 41 million USD, while the Australia SAA Power Cords supplied along with the imported equipment do not comply with country-specific norms. Moreover, the local vendors procure power cords with type D/M plug to complete installation and also on-site electrical safety test is not performed. Hence, this project was undertaken to evaluate the electrical safety of all life-saving equipment purchased in the year 2013, referring to the guidelines of International Electrotechnical Commission 62353, the Association for the Advancement of Medical Instrumentation (AAMI) and National Fire Protection Association (NFPA)-99 hospital standard for the analysis of protective earth resistance and chassis leakage current. This study was done with a measuring device namely electrical safety analyser 612 model from Fluke Biomedical.


The power source for all equipment is alternating current (AC) with frequency - 50Hz; unfortunately, humans are most sensitive to this frequency.[1] Some of the effects are tissue injury, burns, and fibrillation of the heart.[2] The main cause for these effects are leakage current which occurs naturally in all the electrically operated equipment due to stray capacitance between two wires or wire and metal chassis. This can be eliminated by generating a low resistance path from equipment to ground, ideally at zero potential.

Though the equipment is designed with the highest degree of protection, safety is attained only when there is a proper connection between the equipment and hospital earth by a component called power cord. If the protective earth resistance (PER) is not as per the International Electrotechnical Commission (IEC) norms, the safety of equipment is violated. Therefore, during installation of medical equipment, electrical safety test is highly required to conform various safety parameters described by IEC 62353.[3] The initial tested data serves as a reference guide for recurrent test throughout the working lifetime of each equipment. In future, on the recurrent test, the deviations of ground integrity and leakage current can be monitored for necessary corrective actions. It is now clear that all the life-saving equipment must undergo electrical safety test on recurrent intervals to ensure safe operation.

The purpose of this project was to find out the root cause and influence of environmental factors for equipment failures during the first year of purchase. In addition, implementing electrical safety checks on recurrent intervals to guarantee safe usage of equipment on the patient are discussed.

We conducted electrical safety study on 200 life-saving equipment purchased in the year 2012–2013 in Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry [Table 1]. They belonged to Class I category with detachable Swiss SEV Power Cords of power consumption <1.5 KVA (kilovolt ampere). Class II category, non-detachable power cord equipment and permanently installed equipment were excluded from the testing. Since all the tested equipment were newly purchased, the influence of film resistance was excluded.[4] The electrical safety analyser (ESA) 612 model was used which is capable of measuring low resistance up to 2 Ω with an accuracy of ±2% and leakage current from 0 μA to 1999 μA with an accuracy of ±1%. The analyser incorporates test algorithm of Association for the Advancement of Medical Instrumentation(AAMI)/National Fire Protection Association (NFPA)-99 hospital standard and IEC 62353.[5] All the measurements were manually obtained for better accuracy.

With today’s need for electronic equipment, manufacturers are realizing that in order to prosper—and in some cases to survive—they may have to export to global markets. When designing for global markets, a number of factors are involved, such as being able to provide equipment that is easily adaptable to the needs of the consumer, without any reconfiguration on their part.

One of the main considerations is to ensure the end-user has the correct means of connecting to their local mains supply. It’s also important to follow standards and country-specific regulations. Choosing the right components in the product design is essential as is identifying them in ways that others can understand.

Sometimes electrical terminology can be confusing because different people use different terms to mean the same product. For example, words that describe the means of connecting electrical equipment to a power source may be called a detachable or non-detachable cord, an appliance cord, a cable, a cable assembly, an interconnection, or a power supply, to name a few. They may also be called a power cord, a cord set, a jumper cord, and a connector power cord.

For the purpose of this article, the following terms, which are used at Interpower, will be defined: power cord, jumper power cord, connector power cord, cord set, and jumper cord set.

Hallo Community, 

vor kurzem hat mich ein Freund durch sein Gartenhaus geführt und er hatte diese kleinen Skalpelle, die mich wirklich beeindruckt haben... Ich war so beeindruckt von der Funktionalität, dass ich mir selbst welche kaufen möchte. 
Ich habe zum Beispiel dieses hier gefunden: https://curt-tools.com/cuttermesser-kauf...ni-cutter/

Es gibt noch ein paar andere Online-Shops, die ich gefunden habe, aber der hier ist bis jetzt mein Favorit. Benutzt sonst noch jemand Mikro-Sicherheitsmesser? 

Ich bitte um einige Empfehlungen.

Vielen Dank! 

Kann mir jemand hier helfen, was ich mit dem Handel von Krypto beachten sollte?

Habt ihr Tipps?

Risk-Optimal Arrangement of Stiffeners in Steel Plate Shear Walls
Placement of ferritic stainless steel plate shear walls in the building cores around the elevators and stairs necessitates door-type openings in these systems. Because of large dimensions of door openings, the energy dissipation capacity drops significantly and thus, the probability of out-of-plane buckling under lateral load increases. Accordingly, introducing stiffeners around the opening increases the amount of dissipated energy and improves the performance of the SPSW system. This paper evaluates the seismic risk of SPSW systems with different arrangements of stiffeners around the door opening. Risk, in this context, denotes the probability of failure times the cost of failure of a given SPSW. The probability of failure is computed through a finite element reliability analysis in which material properties, element geometries, and the lateral force are random variables. The failure event is described by a limit-state function as the exceedance of the drift ratio of the SPSW from a prescribed threshold. The drift ratio is computed by subjecting the finite element model to non-linear static analysis in ABAQUS. The reliability analysis is conducted for a variety of single-story SPSW models having door opening with different arrangements of stiffeners and also for a typical SPSW model without opening as a base model. Next, decision analysis is employed to identify the optimal arrangement, i.e., the one that is associated with the minimum risk. Finally, the effect of risk aversion on the optimal decision is studied by introducing risk-averse utility functions with different degrees of risk aversion.

Introduction
A typical 304 stainless steel plate shear wall (SPSW) consists of an unstiffened thin infill plate connected to vertical and horizontal boundary frame members, i.e., columns and beams, respectively. The lateral load is transferred through the infill plate by the principal tension stresses, as shown in Figure 1A. The infill plate is allowed to buckle in shear and consequently forms a diagonal tension field during an earthquake. Previous studies, both experimentally and numerically, have shown that this system exhibits a high ductility and hysteretic energy dissipation capacity compared with conventional braced frames and concrete shear walls (Caccese et al., 1993; Elgaaly et al., 1993; Berman and Bruneau, 2003). Another advantage of SPSWs is the ability to provide openings in the infill plate, which may be required for architectural purposes. Roberts and Sabouri-Ghomi (1992) conducted the first study on SPSW systems with opening. They performed a series of cyclic quasi-static testing on unstiffened SPSWs with a circular opening located at the center of the plate. All the SPSWs tested exhibited stable S-shaped hysteresis loops and adequate ductility. They showed that the strength and stiffness of a perforated SPSW can be approximated conservatively by applying a linear reduction factor to the strength and stiffness of a similar unperforated SPSW. Daftari and Deylami (2000) studied the effect of plate thickness, opening height to width ratio, and the areal percentage of the opening for more than 50 different SPSWs with a central rectangular opening. They determined the optimum aspect ratio for the opening. Paik (2008) obtained a closed-form empirical formula for predicting the ultimate shear strength of 316 stainless steel ship plate with central circular opening under shear loading by the regression analysis. Pellegrino et al. (2009) investigated the influence of the dimension, position, shape (circular or rectangular), and orientation of a hole with respect to the panel slenderness and aspect ratio in steel plates with one perforation subjected to shear loading. Valizadeh et al. (2012) experimentally evaluated the effects of opening dimensions and slenderness factors of plates on the seismic behavior of SPSWs with a circular opening at the center of the panel. Sabouri-Ghomi et al. (2012) studied the behavior of both stiffened and unstiffened SPSWs with a single rectangular opening with different sizes and locations through a non-linear finite element analysis. Hosseinzadeh and Tehranizadeh (2012) studied the non-linear behavior of SPSWs with fully-stiffened large rectangular openings used as windows or doors. Alavi and Nateghi (2013) experimentally investigated the seismic behavior of SPSWs with a central perforation along with diagonal stiffeners. Bhowmick (2014) developed a shear strength equation for unstiffened perforated SPSWs with a circular perforation at the center. They assessed the proposed equation by analyzing a series of single-story perforated SPSWs with different aspect ratios and different perforation diameters. Sabouri-Ghomi et al. (2015) experimentally studied the structural behavior of stiffened SPSWs with two rectangular openings and with different separations subjected to cyclic loads. Also, they determined the shear stiffness and ultimate shear strength of the SPSWs theoretically through the plate-frame interaction model.

Placement of SPSWs in the building cores around the elevators and stairs necessitates door-type openings. Furthermore, because of large dimensions of door openings, the energy dissipation capacity drops significantly and thus, the probability of out-of-plane buckling under lateral load increases. Accordingly, introducing stiffeners around the opening increases the amount of dissipated energy and improves the performance of the SPSW system, as recommended by AISC Design Guide 20 (AISC, 2007).

However, construction of those SPSWs in which the vertical and horizontal stiffeners continue to boundary elements, as shown in Figure 1B, is significantly costly. The underlying reasons are the need for more nickel alloy steel and significantly more cutting and welding for connections, which requires further material, labor, and quality control. As shown later in the paper, based on Iran's Cost Catalog (Planning Budget Organization, 2016), the cost will increase by 15%. The extra stiffeners also elongate the construction process and entails workmanship difficulties and defects. The present paper is the first to evaluate the seismic risk of SPSW systems with different arrangements of stiffeners around the door opening. Risk, in this context, denotes the probability of failure times the cost of failure of a given SPSW. The probability of failure is computed through a finite element reliability analysis (Ghanem and Spanos, 1991; Der Kiureghian and Zhang, 1999; Haldar and Mahadevan, 2000; Imai and Frangopol, 2000; Sudret and Der Kiureghian, 2002; Haukaas and Der Kiureghian, 2007) in which material properties, element geometries, and the lateral force are random variables. The failure event is described by a limit-state function as the exceedance of the drift ratio of the SPSW from a prescribed threshold. The drift ratio is computed through a finite element model under non-linear static analysis in ABAQUS (Karlsson and Sorensen, 2013). The reliability analysis is carried out for a variety of single-story SPSW models that include door openings with different arrangements of stiffeners and also for a typical SPSW model that lacks the door opening as a base model. Then, the risk-optimal arrangement is identified through decision analysis. Finally, risk-averse utility functions are introduced to study the effect of risk aversion on the optimal decision.

The single-story SPSW considered in this research, is part of a symmetrical office building located in Tehran, Iran. The floor plan of the building and the considered SPSW is shown in Figure 2A. The roof dead and live loads are assumed 0.5 and 0.15 ton/m2, respectively. Also, Figure 2B illustrates the base SPSW model, i.e., the one without opening. The height and bay width of this model are assumed 4 and 6 m, respectively. Frames other than those containing SPSWs are gravity frames and therefore, SPSWs carry the entire lateral load. Also, gravity loads are not carried by beams of the considered SPSW and transmitted by transverse beams to beam-column connections. The structure is designed for a very high seismic zone with a site-specific earthquake acceleration of 0.35 g according to the Iranian Seismic Code (BHRC, 2014).

The SPSW is designed based on the recommendations of AISC Seismic Provisions (ANSI/AISC 341-16, 2016) and AISC Design Guide 20 (AISC, 2007), which presents a capacity design method for SPSWs with solid infill plates. The section for boundary beams is selected to carry the forces due to the yielding of the infill high-strength 2507 stainless steel plate, and the section for the columns is selected to carry the forces developed in the yielded infill plate and the plastic hinges at the ends of the top beam. Also, in order to ensure inelastic beam action at the anticipated points and to reduce the bending moment demand to columns, the beam-column connection details include reduced beam sections (RBS) at both ends. Thus, the “weak beam-strong column” criterion is guaranteed. The RBS dimensions are designed in accordance with AISC 358-16 (ANSI/AISC 358-16, 2016). The sections of beams, columns, and stiffeners for the SPSWs are W360X287, W310X202, and W310X28.3, respectively.

The door-type opening is conventionally introduced at the mid-span, as shown in Figure 3. The horizontal and vertical dimensions of the door opening are assumed 1.5 and 2.5 m, respectively. Figure 3 shows the six considered arrangements of stiffeners around the opening. Arrangement 1 is the recommendation of AISC Design Guide 20 (AISC, 2007). In the other arrangements, all different combinations of the proposed vertical and horizontal stiffeners are considered. It will be shown later in the paper that the code arrangement is the most conservative one amongst all, and will only be optimal if the designer is extremely risk averse. For this reason, arrangements that are more conservative than this arrangement, i.e., the ones which have more stiffeners, are not included in the analysis.

A Reluctant Online Furniture Shopper Orders Article's Most Popular Sofa
Moving is the worst. Everyone knows there’s no joy to be found sorting through all your things, packing up whatever you keep, and then paying someone to lug it out, or worse, having to do it yourself. But decorating the new place, that’s the fun part, right? For me, it was debatable.

When I was getting ready to move into a one-bedroom apartment in Brooklyn with my boyfriend, John, I loved the idea of decorating with a fresh slate. (All of my “saved” posts on Instagram from aspirational home decor bloggers could finally be put to good use!) But as I said, I loved the idea of it all. Actually executing my plans proved way more difficult than I had anticipated. There are just so. many. options.

John doesn’t get as jazzed as I do about entryway ideas or which chairs look right with our farmhouse table, so I couldn’t count on him to help pick the small stuff. But the couch he was invested in. It’s where we’ll spend most of our time and undoubtably what we’d spend the most money on, so it had to be right.

We knew we wanted a camel-colored leather style, so that helped narrow things down a little. But we were still swimming in a sea of options. West Elm had some gorgeous sofas but the long delivery times meant we’d be without a couch for 5+ weeks. (Yes, I should have planned better. Shush.) That was out.

RELATED: We Tried It: The 3D Decorating Tool Everyone Will Use in the Future

We struggled with the idea of buying a couch online at all since we couldn’t actually sit on it first. And because sites like Wayfair and AllModern sell so many different brands, it’s hard to properly research or hear firsthand from someone who’s purchased that exact couch.

The journalist in me wanted multiple sources to confirm I was going to love this couch. There is just so much trust you can put in an anonymous reviewer.

Then I found myself on Article‘s site. The online-only, direct-to-consumer brand had the style I was looking for — the Sven tan sectional — and it could be delivered within 10 days, potentially even quicker. I’d heard from friends who had good experiences with the brand. The only complaints I could find online were that the back cushions weren’t very firm, and the color is lighter than expected. I know that a beautiful patina takes time, and I sleep on the plushest mattress known to man so I wasn’t too worried about either. They also have a pretty great return policy, which eased my mind. If I wanted to exchange, it’s free, or returns are $49. I would just need to hang on to the packaging until I was sure, otherwise it’s an extra $50.

Honestly, taking out my credit card to pull the trigger on such a large purchase was the hardest part of the whole ordering process. It retails for $2,999 with the chaise, or $1,799 without.

I placed my order and got a call five days later that it was time to schedule my delivery. I had the flexibility to pick whatever day I liked, but was limited to the window of time they assigned to me 24-hours before, so it’s best to pick a day you have completely free.

I did not do this. Learn from me.

I scheduled mine for my actual move-in day, so with my movers coming in the morning to my old place, I crossed my fingers for a later delivery window. Naturally, I was assigned 8:30 a.m.-12:30 p.m. (See, not a good planner.) It was going to be a hectic day.

RELATED: We Tried It: Can a Foam Mattress in a Box Really Replace Your Old Spring Bed?

I asked their customer service team to give me a 30-minute heads up, and they happily obliged. When I got the call, I rushed over to the new apartment to find a big Article truck on my block. My landlord wasn’t quite ready for me, so the delivery men ended up having to leave my couch in the hallway. They would have put it in my living room because I opted for the “inside room” delivery option, which was $50.

Shipping is free for orders over $999 if you only want it delivered to the ground floor of your building. It’s $120 (with a discounted rate for orders over the $999 mark) if you want them to bring it inside and assemble it, but I wouldn’t recommend shelling out the extra bucks because it’s so easy to do yourself (more on that below).

Me and my new couch were off to a rough start, but things only got better once we got it inside. The Sven sectional comes in two big pieces so there’s not a whole lot of assembly required. All you need to do is screw on the legs and align the latch that joins the two pieces securely together. John actually said he thought it was the easiest thing we did that day.

Now that we’ve had nearly two months to settle in with our couch, I’ve grown to love it even more than expected. It’s incredibly comfortable — I didn’t find the cushions to be under-stuffed, but rather just right. You can lean back and settle in, without feeling like you’re stuck in that position till the end of time. The reviews were right about the color, though. It doesn’t have that rustic, lived-in look fresh out of the box. That will come the more we use it. I’m excited to see what it’ll look like six months from now.

The leather is soft, but not precious. I’ve already spilled more drinks on it than I care to admit and it’s almost like the liquid rolls right off. And I think any marks that do appear add to the character.

It’s also deeper and more spacious than most of the other couches I considered, which has been a treat. John and I can sprawl out simultaneously. The chaise is huge in fact. My apartment is not even 600 square feet, so if I was going to take up most of the living room with a sectional, it needed to be one that we didn’t want to get up from. And so far, we haven’t!
After tossing around a few different options for a new couch, my husband and I decided to purchase an Article Sven sofa in December of 2016. When we first bought it, we loved the look of it and were happy with it. The down filling and soft leather made for a very comfortable fabric sofa. After having this couch for about a year though, I started noticing how quickly it was losing shape. The seat cushion started hanging over the edge, the leather piping had become crooked and pinched along the armrests, down feathers frequently came out of the seams, but most disappointingly, the back cushions had slouched into a flat pile of worn leather. Down filled cushions will understandably need fluffing, but the issues with these flat cushions go so far beyond a normal flattened cushion. It’s gotten to the point where the back frame has become worn where the cushion has failed to sit upright and it looks ragged. I’ve meticulously cared for the couch according to Article’s care guide; vacuuming weekly, cleaning with a damp cloth, and using Otterwax regularly on top of fluffing and trying to whip the cushions back in shape. Needless to say that in the 2 years since spending almost $2000 on this sofa, I’m really disappointed with my purchase. I feel like I got a defective sofa because in photos that I’ve seen online or on social media of the couch, it has firm, stuffed cushions and the seat doesn’t hang over the edge like mine does. Has anyone else had issues with their Sven? What can I do?!
Fast-forward to July 2020, when I signed a new lease with an August 1 move-in date. After landing a new job and immediately being thrust into a country-wide quarantine, I finally returned to New York City, feeling proud to be in a position that allowed me to upgrade from my previous terrible, small apartment. My newer space would be bigger and brighter than my previous cramped, flex-walled dungeon. I couldn’t wait to move in—and, of course, to decorate.

As a Fashion & Lifestyle Editor, I’m constantly on Instagram looking at what people are wearing, how they’re decorating their spaces, etc. A large part of my job is seeking out inspo and seeing what’s trending, and as I focused my sights on all things home decor, I kept seeing the same couch popping up again and again: Article’s Sven Charme Tan 72″ Sofa. There it was, featured in a sponsored post by an influencer I sometimes sit with during Fashion Week. Then again, with an LA-based model lounging effortlessly atop it. I started to see it everywhere.

Our mission at STYLECASTER is to bring style to the people, and we only feature products we think you’ll love as much as we do. Please note that if you purchase something by clicking on a link within this story, we may receive a small commission of the sale.

I scrolled and scrolled, but I couldn’t escape this couch. I knew deep down that it was time for me to ditch my foul freebie couch and give my new apartment the upgrade it deserved, but I couldn’t help but wonder if the Sven Sofa was too good to be true. I mean, everything looks better on Instagram, right? Was it really an incredible couch, or just the most convenient sponsorship a gal could get?

I reached out to Article, totally transparent about my suspicions, and let them know I wanted to review the leather sofa and see if it was actually worth all the hype. They agreed with some majorly confident energy, which implied that they already knew damn well how good their product was, and weren’t worried about the risk of a potentially-negative review. After going back and forth (and back and forth, and back and forth…) about whether to get the Sven in leather or Grass Green Velvet, I finally selected the Charme Tan Leather, convinced it was the appropriate Big Girl Choice for my Big Girl Apartment.

I admit, I was nervous about receiving a couch in the middle of a pandemic, but Article’s Contactless Delivery was a breeze. Assembly went without a hitch, and before I knew it, a big, beautiful leather couch took up an entire wall of my new apartment. My apartment. My couch. As someone who had only ever had hand-me-down or found furniture in the past, I was over the moon.

And now, my honest review of the quality. I don’t want to be a suck-up, but wow. I was genuinely convinced this would be one of those ~ridiculously gorgeous, but not actually all that fabric sectional sofa, and I was dead wrong. It’s comfy AF, and given that I’m currently working from home, I sit on it basically all day, every day. There’s just the right amount of give when you sit that allows a cushy feel, but the second you stand up, the couch resumes its aesthetically-pleasing, structured shape.

Another great thing? I had feared a leather couch because I didn’t want to scratch or stain it, but the Charme Tan Leather comes with a slightly lived-in look, so it’s not one of those too-perfect-to-sit-on situations. I’m careful, of course, but I don’t feel like enjoying a glass of wine or sitting with shoes on are majorly risky moves. The leather looks and feels durable, and I appreciate that it can handle some wear and tear.

I know it can be scary to splurge on a large piece of furniture, especially for the first time, but I’d definitely recommend the fabric corner sofa to both home-owners and apartment renters. Having such a large, beautiful piece really pulls my home together, and it’s something I know I can take with me wherever I live next. I’m glad I didn’t end up buying a cheaper, low-quality couch for a quarter of the price that I’d eventually replace.

Plus, I finally understand why I kept seeing this couch all over my Instagram feed: it’s so photogenic. I use it as a backdrop for just about all of my flatlays, and I’ve taken many a self-timer photoshoot posing on it. No shame!

Guide to Essential Oil Diffusers
Essential Oil Diffusion is the process of dispersing essential oils so that their aroma fills a room or an area with the natural fragrance. From the simple to the elaborate, many different methods exist for diffusing essential oils into a room. Three easy aromatherapy diffusion methods exist which can be done with things you probably already have in your household. In addition, there are numerous bluetooth diffuser and diffusing devices available for purchase. This article will detail the different types of devices and methods that may be used.

The descriptions below are generalities about the different aromatherapy diffusers and other essential oil diffusion products that are available. Always check the specifications, requirements and safety comments supplied with the particular product you are interested to confirm that it is suitable for your needs and expectations.

Ultrasonic diffusers use water and ultrasonic waves to diffuse essential oils into the room. They come in different sizes, and some feature colored lights.

Ultrasonic Essential Oil Diffuser Benefits:
Various types of ultrasonic aromatherapy diffusers are available, allowing consumers to choose from a wide range of sizes and options. Of non-passive style wifi aroma diffuser, ultrasonic diffusers tend to be amongst the most affordable of aromatherapy diffuser types, and they are becoming widely available. While diffusing essential oils into a given space, they also can humidify the room.

Disadvantages:
Despite the advantages, ultrasonic diffusers can fail more quickly or be more problematic. Generally speaking, I tend to hear more complaints from users of ultrasonic diffusers than for other aromatherapy diffuser types. It is important to always follow the usage instructions for the ultrasonic model diffuser that you purchase.

An atomizing diffuser (also known as a nebulizer) is a device that takes essential oils and breaks them into separate molecules before dispersing the smaller molecules into the room. It is said that these smaller molecules can be more readily absorbed by the lungs and thus create greater therapeutic value than by use of other diffusion methods.

A nebulizer is a small device that consists of two main parts: the plastic base that contains the motor/pump and a very unusual, clear blown-glass piece that holds and "nebulizes" the oils. Instead of the use of the unusual glass piece, some atomizing diffuser use a special bottle that looks like a Boston round bottle.

The size of the pump that accompanies the atomizing diffuser makes a big difference in the speed in which the essential oil is nebulized and in the amount of room/area coverage that the nebulizer can accommodate.

Essential Oil Nebulizer Benefits:
For therapeutic use, an atomizing diffuser/nebulizer should be considered. It is said that nebulizers can supply greater therapeutic benefit than the use of other aromatherapy diffusers because they break the oils down into smaller molecules.

Disadvantages:
Compared to other methods, cleaning the atomizing diffuser/nebulizer, especially after using thicker essential oils can be time consuming. Depending on the style of the light wood grain aroma diffuser, thick oils such as Sandalwood and Patchouli usually cannot be used (unless first well blended with much thinner oils) as they can clog certain model diffusers.

Fan diffusers come in a variety of sizes, shapes and styles. Essentially, a fan diffuser uses a fan to gently circulate air across the essential oils, allowing them to evaporate into the air more actively than with passive aromatherapy diffusion. To use a fan diffuser, essential oils are usually placed onto a disposable absorbent pad or into a tray. The pad or tray is placed into the aromatherapy diffusion unit and then powered on. The fan then blows air across this pad or tray and carries the aroma throughout the room. Since fan diffusers come in a variety of sizes, some fan diffusers will only diffuse a small room whereas others can diffuse very large areas.

Fan Style Essential Oil DIffuser Benefits:
Fan style aromatherapy diffusers are available in a wide variety of brands and styles. Depending on the brand and model, fan diffusers can fragrance a large area. Fan diffusers are generally easy to use. Some fan diffusers are powered by both electricity and batteries, making them quite portable.

Disadvantages:
Some fan diffusers, depending on the brand and model, require the purchase of replacement absorbent pads. Some fan diffusers are noisy.

Heat diffusers use heat to gently heat the oil and disperse the aroma into a room.

Fan Style Essential Oil Diffuser Benefits:
Electric heat diffusers may fragrance larger areas, depending on the brand and style. They can also help to more efficiently disperse the aromas of thicker oils such as Sandalwood and Patchouli.

Disadvantages:
Some individuals have trouble with clean up after using thicker essential oils. However, clean up can be much easier in this type of deep wood grain aroma diffuser than in nebulizers and other aromatherapy diffusers. Usually, alcohol can help to dissolve stubborn, stuck-on essential oil residue.

A candle diffuser is a diffuser that utilizes a tea light or other candle to gently heat the essential oil to promote diffusion into a room. A candle diffuser is usually ceramic or metal. The diffuser has an opening or space for a candle and a little bowl or tray for storing a tiny quantity of essential oil. Candle diffusers come in many shapes and colors from the modest functional piece to those that act both as a work of art and as a candle diffuser.

Candle Diffuser Benefits:
Candle diffusers are usually less pricey than nebulizing diffusers, depending on the style and design. Candle diffusers do not require electricity or batteries.

Disadvantages:
One needs to be as careful with using a candle diffuser as with using candles in general. Also, one must be sure to keep replacement candles on hand.

Terracotta clay and sandstone diffusers go by many names and come in an array of attractive shapes and sizes. Some terracotta diffusers resemble tiny clay pots that accept a small quantity of essential oil. Usually a cork is the method by which the opening is closed. The oils permeate through the pot and then diffuse out into the room. The intensity of the aroma depends on how much essential oil is added to the clay pot or other shaped diffuser. Sandstone is quite porous and is another lovely way to passively diffuse essential oils.

Terracotta and Sandstone Essential Oil Diffuser Benefits:
Clay pot diffusers are very inexpensive, easy to use, and do not require electricity or batteries.

Disadvantages:
The aroma is strongest shortly after adding essential oil to the clay pot and then dissipates as time passes. As such, it’s hard to keep the same level of aroma in the room.

Lamp rings are typically made out of terracotta or brass. They are shaped like a ring and set directly onto a standard light bulb. They have a grooved lip that goes all the way around them. This lip holds the essential oil. The heat from a light bulb heats the essential oil in the lamp ring, and the oil is then gently diffused into the room.

Lamp Ring Aromatherapy Diffuser Benefits:
Lamp Rings are usually inexpensive.

Disadvantages:
If any essential oil gets onto the light bulb, the light bulb could break. They won't work with odd sized bulbs or with bulbs that are situated at odd angles. Lamp rings probably cannot be used with high efficiency bulbs.

Given all we've all been through since the start of a little-known global pandemic, essential logo custom aroma diffuser have become increasingly, well, essential for anyone struggling to wind down. The way they work is actually pretty straightforward (and not all that dissimilar to scented candles and reed diffusers). Drawing on the principles of aromatherapy, the essential oils stimulate the body's reaction to scent, something that has been shown to trigger different emotional and physical responses, helping to create a calming and sleep-inducing environment. 

Whether you want to use essential oil diffusers for sleep, anxiety or even just to imbue your living room with a light, homely fragrance, these diffusers will keep you calm and look good doing it. From ultrasonic diffusers to ones with light options and mist modes, plus the smarts of automatic shut-offs and timer settings and diffusers with the gusto to scent large rooms, we've shone a spotlight on some of the best-selling aromatherapy diffusers you can buy right now, with a bit of information to guide your search. There's a reason they keep selling out…

How do essential oil diffusers help you relax?
The basic principle is actually quite simple: different oils reportedly stimulate different responses in our hypothalamus gland, which then triggers the production of hormones. According to essential oil brand Neom, the hormones then produce different responses within the body as chemical messengers are sent to specific cells, leading to better sleep, less stress, more energy or a mood boost, depending on the oil. Scent can also be linked to our memories, stimulating positive responses in our bodies and helping to relax us in the evenings.

What are the benefits of aromatherapy and essential oil diffusers? And are oil diffusers worth it?
Essential oils may be beneficial for reducing anxiety, Dr Chris George explains: “Some small studies support the use of lavender essential oils for a reduction in stress and anxiety. One study, in particular, used lavender oil preparation Silexan in the treatment of generalised anxiety disorder and compared this to benzodiazepine medication [a commonly prescribed drug for anxiety]. What they found is that the lavender preparation had comparable positive effects on sleep as traditional medication. However, the huge advantage is that the lavender oil did not produce many of the unwanted side effects associated with the medications.

“Currently in the UK essential oils are not prescribed by NHS doctors. These preparations are considered as part of complementary and alternative medicine (CAM), which falls outside of mainstream healthcare,” explains Dr George. “However, this is not to say that there is not a role for essential oils to go alongside everyday medicine.”

What are essential oils?
Derived from roots, seeds, flowers, bark and other natural plant products, essential oils are concentrated compounds that are connected to a plant’s scent, a crucial part of pollination. Far from a recent discovery or wellness trend, the oils have been used for centuries by ancient societies who cited their benefits in healthcare, religious ceremonies, beauty treatments and skincare, oral hygiene and food preparation. 

Which essential oils can you diffuse to help you sleep?
Lavender oil is one of the most commonly used oils to help with sleep disorders. Tisserand aromatherapist Jo Kellett recommends starting with lavender oil and geranium, while the head aromatherapist for Neal’s Yard Remedies recommends frankincense to help slow the breath and calm the mind, before moving on to neroli or camomile. 

As far as home fragrances are concerned, The White Company can do no wrong. Whether you pair it with one of the brand's bestselling home fragrances or not, this electronic diffuser always manages to dispense exactly the right amount of fragrance in a matter of minutes, meaning you can spend more time relaxing than fiddling with different settings. And with a range of timer settings, you can turn it on before you go to bed and trust in the power of an auto shut-off.

Oliver Bonas’ Ceramic Aroma Diffuser is almost always sold out and for good reason. Available in three colours, the ridged design and ceramic cover fit nicely with minimalist home aesthetics, while the colour light settings can set a relaxing mood of an evening. With four different time settings, you can use this overnight and late in the evening to fill your bedroom with a calming mist of fragrance. 

Where Is Stainless Steel Pipe Used?
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With so many different products like seamless pipes, welded pipes and flanges it might be overwhelming trying to pick which seamless steel pipe to use for your business applications, or even what they can be used for in the first place. There are many different properties of each pipe that give it a unique use in its respective industries, and if you’re going to master the different types of piping materials and what they’re used for, it’s important that you learn the different types, what they can be used for and how they can be applied to various industries.

To give you a hand, we’ve put together a simple article that details most of the regular uses for ERW steel pipe, why it’s used and how it could be applied to a generic industrial company.

Types of Stainless Steel Pipe
First, let’s dive into the many different types of stainless steel pipe so that we can judge which types to use for each different scenario.

Seamless Pipe
A seamless pipe is a pipe that does not contain any seams or weld joints. It’s capable of standing up to intense levels of pressure and also temperatures thanks to the metal itself. It’s used in a wide variety of different oil and gas applications, but they are also used in mechanical and engineering industries too. This makes seamless pipes rather versatile and they are always inspected with high levels of precision to ensure the quality of the material.

Welded Pipe
Welded pipes can be used in virtually every industry thanks to its flexibility. However, they fare better in corrosion resistance as opposed to withstanding pressure. Because of the materials used and the lightweight nature of welded pipes, they’re far more cost-effective than most other piping methods and offer the best value for your money.

Flanges
Pipe flanges are another important part of your overall piping setup. These come in many forms such as slip-ons, blinds, lap joints, threaded and semis. These are made from durable and sturdy materials to ensure their reliability and high-quality products are always used when creating pipe flanges.

Spectacle Blinds
For permanent or long-term solutions that allow for isolation of piping sections, spectacle blinds, spades and spacers are used for convenience. If a piece of machinery or piping section needs to be inspected, then spectacle blinds are used so that you can isolate a certain part of the piping in order to maintain a larger system. Since this is an incredibly important role that is crucial to your safety, it’s recommended to rigorously test the reliability of your spectacle blinds if you want to remain safe. Given that each use case is different, it’s recommended that you speak with a professional first before investing a lot of money into spectacle blinds.

Types of Industry where LSAW steel pipe is Used
Now we’ve taken a look at the different types of steel pipe on offer, let’s look at the industries they are used in.

Oil and Gas
Technology plays a massively important role in the oil and gas industries. The need for corrosion-resistant piping has increased over the past couple of years as the depths we explore for oil deepens and more pressure is being placed on the duplex and super duplex stainless steel pipes we use. These harsh environments can be incredibly corrosive and if the damage is left unchecked, the pipes would easily burst and become unusable for deeper depths. This is why it’s important to have sturdy pipes in the oil and gas industry and how it plays such a huge role in the success of this industry.

Nuclear Power
Obtaining usable energy from atomic nuclei is no easy task. All of the nuclear reactors we use today heat water to produce steam which is then used to spin turbines that provide us with energy and most of them are placed near the coast due to the cooling requirements. As such, much of the water being pumped in to cool down these reactors is from the sea, and it needs to be resistant to the corrosive nature of seawater. SSAW steel pipe is more than qualified to defend against corrosion from seawater, hence its importance in the nuclear power industry.

LNG
LNG (liquefied natural gas) is gas that has been temporarily converted into a liquid form for the sake of transportation. Its volume is greatly reduced to make it easier and cheaper to transport. In some cases, transporting natural gas via pipelines isn’t possible or cheap enough to be worth the cost, which is why it’s instead transported via a liquid form in cryogenic sea vessels and road tankers. As such, it’s important to have the right piping that provides safe and economical LNG transport to deliver natural gas to parts of the country or world that are difficult to reach.

Desalination
Desalination is the removal of salt and other minerals from a source of water. This is done to convert water into fresh water that is fit for humans to use or possibly irrigation. In most cases, salt is created as a by-product and desalination are used on many submarines and ships. Today, desalination is typically spoken about when attempting to bring fresh potable water to regions of the world where it is difficult. Saltwater and metals generally don’t mix very well, hence the importance of getting piping in the desalination industry that is able to withstand the natural corrosive properties of salt water.

Mining and Minerals
Mining is the process of extracting materials from the earth. The materials covered are usually in the form of metals both common and precious and it’s something that has been done for thousands of years to acquire beneficial resources. The mining industry is one where stainless steel has made it easier and more profitable to take on larger operations. Whether it’s used in the actual mines itself where workers and machines dig at the earth, or in the bunk beds and mess halls where staff sleep, it’s used in a variety of different applications to provide safety and reliability.
There’s no voodoo when it comes to welding stainless steel tube and pipe – proper selection of filler metals, joint preparation, cleanliness and welding processes help ensure that the final product meets the designated quality standards and retains its intended corrosion resistant qualities. There are, however, evolutions to well-established processes and techniques that allow pipe fabricators to increase productivity without sacrificing the corrosion resistance of the stainless steel. 

This article will cover the basics of welding stainless steel tube and pipe for applications ranging from high purity food and beverage, pharmaceutical and petrochemical pipe to oil and gas applications. Within those basics, we will present best practices and new wrinkles on established methods that may help drive productivity in your shop while improving or maintaining the desired corrosion resistance.  

As a note: critical applications where processes are certified should not be altered without going through appropriate certification processes. Each process detailed in this article has been certified in critical applications and is meant to spur ideas as to how to move your own welding practices forward. 

Filler Metal Selection Critical in Controlling Carbon Levels
Selecting filler metal for pipe fittings is about enhancing the properties of the weld and meeting the requirements of the application. Filler metals with an “L” designation, such as ER308L, provide a lower maximum carbon content, which can help retain corrosion resistance in low carbon stainless alloys. As an example: if you weld a 304L base metal with a standard 308 filler metal, you’ll actually raise the carbon content of that joint and increase the chance of corrosion. In high purity applications – food, beverage, pharmaceutical – that low carbon content is critical for maintaining corrosion resistance. Conversely, a filler metal with an “H” designation provides higher carbon content for applications requiring greater strength, particularly at high temperatures. Filler metals with higher silicon levels, such as ER309LSi, increase weld puddle fluidity, improve tie-ins and increase travel speeds for greater productivity. The 309 series filler metals are also particularly adept at joining dissimilar stainless steels and in overlay applications.      

When welding stainless steels, it’s also important to select a filler metal with low trace (or “tramp”) elements. These are residual elements in the raw materials used to make filler metals. They include tin, antimony, arsenic, phosphorus and sulfur, and can have strong effects on corrosion resistance.

Controlling Sensitization with Filler Metals, Interpass Temperature Control      
Sensitization is the primary cause of the loss of corrosion resistance and is affected by the chemistry of the base material and filler metal, as well as the temperatures at which the weld cools. Chromium oxide is the “stainless” layer of stainless steel. If you raise the carbon levels in the weld and neighboring heat affected zone, it forms chromium carbides, which tie up the chromium, preventing the formation of chromium oxide. This in turn allows the steel to corrode or it will not have the intended corrosion resistance.      

There are three primary ways to combat sensitization: the first is to use a low carbon base and filler metal to reduce or eliminate carbon in the welding application. This method, however, is not always practical as carbon is a vital alloying ingredient in some applications.      

The second is to minimize the time the weld and heat affected zone spend at temperatures conducive to sensitization. That range will vary depending on whom you ask, but a general consensus puts that range between 500- and 800-degrees Celsius. The shorter the time spent in that temperature zone, the less damage that accrues from the heat of welding. As such, it is important to adhere to maximum interpass temperatures identified in welding procedures. The goal in multi-pass applications should be to use as few passes as possible and weld at the lowest heat input possible to achieve faster cooling.      

The third is to use filler metals with special alloying ingredients to prevent the formation of chromium carbides. For instance, titanium and niobium can be alloyed into the filler metal and help prevent reactions between chromium and carbon. These elements also have strong effects on strength and toughness, limiting the applications in which they are useful. They also do not provide any benefit to the areas farthest away from the weld in the heat affected zone. 

Shielding Gas Critical in Retaining Corrosion Resistance     
Welding stainless steel tube and pipe traditionally requires a back purge of argon. In non-critical applications, where cost is a driving factor, nitrogen can also be used as a back purge but it may lead to the formation of some nitride compounds in the weld root, which sacrifices some corrosion resistance. This can be an acceptable trade-off in applications such as stainless steel piping for large compressed air systems and hydraulic fluid systems where water is not normally present inside the pipes and the risk of corrosion from the inside is low. 

Straight argon is recommended for gas tungsten arc welding (TIG) of stainless steel tube and pipe. Shielding gas selection for wire processes is more complicated. 

Traditionally, MIG welding has relied on mixtures of argon and carbon dioxide, argon and oxygen, and 3 gas mixtures based on helium, argon and carbon dioxide. These mixes usually contain mostly argon or helium, with carbon dioxide comprising less than 5 percent of the total gas mix. That is because the carbon dioxide can decompose in the arc and contribute carbon to the weld pool, creating a sensitized weld that is vulnerable to corrosion. Pure argon isn’t used with the MIG processes because it doesn’t easily support a stable welding arc. Other trace constituents like carbon dioxide and oxygen can serve this role. Argon and oxygen gas mixes can only be used to weld in the flat position because the oxygen makes for a very fluid molten weld puddle. Argon/carbon dioxide in combination with Pulsed MIG can be used to weld in all positions, as can the Tri-Mix shielding gas mixtures. 

Flux-cored wires for welding stainless steel are designed to run on traditional 75/25 percent argon/carbon dioxide mixes. The flux ingredients prevent the carbon contributed by the shielding gas from contaminating the weld and the fluxing action of the slag covering scavenges the excess carbon and keeps it from entering the weld deposit.   304 stainless steel can be successfully welded using the Regulated Metal Deposition (RMD™) process without a back purge. This is not true for duplex stainless steels. These must be purged with an inert gas such as argon.  

Weld Preparation and the Importance of Fit-Up
A discussion on welding stainless steel tube and pipe is not complete without a discussion on joint preparation. The normal trappings of welding stainless steel apply: use dedicated brushes, files and grinders that never touch carbon steel or aluminum. Cleanliness is critical. Even trace elements of foreign materials incorporated into the weld joint can cause flaws and lead to reduced corrosion resistance and strength. Because stainless steel is so sensitive to heat input to maintain its properties – both in shape and corrosion resistance – the way the pipe is cut and beveled can also have a detrimental effect on the weld. Any gap or lack of fit-up requires the welder to add more filler metal and can slow the welding process down, leading to buildup of heat in the affected area. You want as close to perfect fit-up as possible, especially on sanitary and high-purity tubing. 

The problem of corrosion of steel pipes in hot water supply systems is very relevant in Russia. In a number of cases, the accelerated corrosion of pipelines and fittings installed in hot water supply networks is observed. The purpose of this study is to investigate the mechanism of corrosion of steel zinc-coated and non-galvanized pipes in hot water supply systems, to analyze the causes of corrosion and to develop methods for identifying active corrosion processes occurring in water supply systems. According to literature review the microstructure and composition of the zinc coating and the methods of its application are studied. A SEM/EDS study of the structure and elemental composition of inner zinc coating on new and used steel galvanized pipes is conducted. This study shows the nonuniform distribution of zinc layer which can lead to a rapid corrosion of both the zinc layer and the metal substrate and the development of pitting corrosion. A structure and composition of corrosion sediments formed on the inner surface of pipes was studied. The different causes and factors of steel corrosion in hot water are considered and discussed. A method of corrosion identification of galvanized pipes and heat exchange equipment based on the determination of corrosion products, in particular zinc and copper, was proposed.