Paket Umroh Plus Turki,
Cara Memilih Material Pipa

"PIPA SEAMLESS" Material pipa ada berbagai jenis. Bagaimana cara untuk menentukan material yang harus digunakan? Untuk dapat menentukan material, terutama untuk bidang industri, faktor yang paling penting adalah fluida apa yang akan mengalir didalamnya. Selain itu, kondisi luar dari pipa juga akan mempengaruhi. Dan terakhir, tentu saja dalam sisi ekonomi juga akan menjadi dasar pemilihan material.
Pipa juga dapat dibagi menjadi 2 bagian besar. Pipa dari logam dan non-logam. Logam telah terdiri dari carbon steel, stainless steel, aluminium, nickel dan lainnya. Berikut ini adalah contoh dalam desain pipa untuk pabrik industri gas alam, minyak, atau pabrik kimia lainnya.
Pertama, insinyur proses harus bisa menghitung apa dan berapa banyak macam kandungan yang akan melewati pipa. Pada dasarnya, semua pipa untuk proses biasanya harus memakai pipa logam dan dimulai dari material carbon steel yang paling murah.
Akibat aliran fluida, bagian dalam pipa akan mengalami korosi, dan salah satu cara untuk dapat menetapkan kecepatan korosi adalah memakai grafik de Waard – Milliams nomograph. Grafik ini membantu untuk dapat menentukan berapa kecepatan korosi (mm/tahun) yang telah disebabkan adanya kandungan CO2 dalam fluida.
Problem disebabkan korosi juga dapat diatasi dengan menambah ketebalan pipa sebesar kecepatan korosi dikali tahun lamanya pabrik didesain. Tetapi, jika total ketebalan yang dibutuhkan untuk dapat mengatasi korosi itu terlalu tebal, pipa akan menjadi sangat tebal dan tidak efektif dalam pembangunannya. Untuk keadaan ini, pipa dari stainless steel telah menjadi pilihan selanjutnya.
Selain korosi, suhu fluida juga dapat menentukan material pipa. Semakin rendah suhu, logam akan menjadi mudah mengalami retakan. Ini karena sifat brittle (getas)  logam bertambah pada suhu rendah . Stainless steel merupakan salah satu yang tahan akan suhu rendah. Karena itu, untuk cryogenic service (fluida dengan suhu operasi dibawah -196 degC) stainless steel adalah material yang cocok dibandingkan dengan carbon steel.
Stainless steel sering disebut juga corrosion resistance alloy (campuran logam tahan korosi) dan tentunya akan lebih mahal jika dibandingkan carbon steel. Stainless steel bisa dibagi menjadi beberapa jenis, contohnya austenitic, feritic, martenistic, duplex dan high alloy stainless steel (campuran tinggi logam stainless steel). Sayangnya, stainless steel tidak tahan terhadap semua jenis korosi, terutama korosi yang disebabkan oleh klorida, sulfida serta fluida asam (sour fluid) lainnya.
Untuk sistem pipa yang mengalirkan fluida asam (piping system for sour service) biasanya di desain berdasarkan standar NACE (National Association of Corrosion Engineers) MR0175. Mulai tahun 2003, standar NACE MR0175 bersatu dengan ISO 15156 dan yang telah memiliki syarat desain yang sulit dibandingkan edisi tahun sebelumnya.

Berdasarkan NACE MR0175/ISO 15156, penggunaan austenitic stainless steel telah dibatasi oleh kombinasi dari kadar khlorida, H2S (hydrogen sulfide) dan suhu fluida. Jika austenitic stainless steel tidak dapat digunakan, maka penggunaan duplex atau high alloy stainless steel merupakan pilihan selanjutnya. Jika duplex atau high alloy stainless steel juga tidak dapat digunakan, maka pilihan selanjutnya adalah menggunakan logam campuran nikel seperti incoloy dan inconel.
Semakin tahan terhadap berbagai korosi, semakin mahal harga material tersebut. Untuk dapat mengurangi biaya, pengaplikasian cladding atau overlay juga merupakan salah satu alternatif. Misalnya dengan menggunakan pipa dari carbon steel dengan dilapisi logam mahal pada bagian dalamnya saja yang bersentuhan langsung dengan fluida sumber korosi akan bisa menekan biaya tanpa mengurangi ketahanan terhadap korosi.
Pemilihan material ini bukan hanya untuk pipa, tetapi juga berlaku untuk bejana (vessel), katup (valve) dan elemen pipa lainnya. Untuk katup, walaupun material dari badan katup bisa memakai carbon steel, tetapi bagian dimana korosi tidak diperbolehkan untuk dapat menjaga kemampuan katup untuk menyekat (sering disebut sebagai trim, seperti bagian valve seat, stem dan lainnya), maka penggunaan stainless steel atau logam tahan korosi lainnya menjadi keharusan.
Pada saat melakukan pemilihan material yang sebenarnya, mungkin tidak akan semudah yang dijabarkan diatas, tetapi secara umum, begitulah proses pemilihan material pada saat mendesain pabrik industri.

Editor : Dian Sukmawati


WASHINGTON — A decade after emergency trailers meant to shelter Hurricane Katrina victims instead caused burning eyes, sore throats and other more serious ailments, the Environmental Protection Agency is on the verge of regulating the culprit: formaldehyde, a chemical that can be found in commonplace things like clothes and furniture.

But an unusual assortment of players, including furniture makers, the Chinese government, Republicans from states with a large base of furniture manufacturing and even some Democrats who championed early regulatory efforts, have questioned the E.P.A. proposal. The sustained opposition has held sway, as the agency is now preparing to ease key testing requirements before it releases the landmark federal health standard.

The E.P.A.’s five-year effort to adopt this rule offers another example of how industry opposition can delay and hamper attempts by the federal government to issue regulations, even to control substances known to be harmful to human health.

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Document: The Formaldehyde Fight

Formaldehyde is a known carcinogen that can also cause respiratory ailments like asthma, but the potential of long-term exposure to cause cancers like myeloid leukemia is less well understood.

The E.P.A.’s decision would be the first time that the federal government has regulated formaldehyde inside most American homes.

“The stakes are high for public health,” said Tom Neltner, senior adviser for regulatory affairs at the National Center for Healthy Housing, who has closely monitored the debate over the rules. “What we can’t have here is an outcome that fails to confront the health threat we all know exists.”

The proposal would not ban formaldehyde — commonly used as an ingredient in wood glue in furniture and flooring — but it would impose rules that prevent dangerous levels of the chemical’s vapors from those products, and would set testing standards to ensure that products sold in the United States comply with those limits. The debate has sharpened in the face of growing concern about the safety of formaldehyde-treated flooring imported from Asia, especially China.

What is certain is that a lot of money is at stake: American companies sell billions of dollars’ worth of wood products each year that contain formaldehyde, and some argue that the proposed regulation would impose unfair costs and restrictions.

Determined to block the agency’s rule as proposed, these industry players have turned to the White House, members of Congress and top E.P.A. officials, pressing them to roll back the testing requirements in particular, calling them redundant and too expensive.

“There are potentially over a million manufacturing jobs that will be impacted if the proposed rule is finalized without changes,” wrote Bill Perdue, the chief lobbyist at the American Home Furnishings Alliance, a leading critic of the testing requirements in the proposed regulation, in one letter to the E.P.A.

Industry opposition helped create an odd alignment of forces working to thwart the rule. The White House moved to strike out key aspects of the proposal. Subsequent appeals for more changes were voiced by players as varied as Senator Barbara Boxer, Democrat of California, and Senator Roger Wicker, Republican of Mississippi, as well as furniture industry lobbyists.

Hurricane Katrina in 2005 helped ignite the public debate over formaldehyde, after the deadly storm destroyed or damaged hundreds of thousands of homes along the Gulf of Mexico, forcing families into temporary trailers provided by the Federal Emergency Management Agency.

The displaced storm victims quickly began reporting respiratory problems, burning eyes and other issues, and tests then confirmed high levels of formaldehyde fumes leaking into the air inside the trailers, which in many cases had been hastily constructed.

Public health advocates petitioned the E.P.A. to issue limits on formaldehyde in building materials and furniture used in homes, given that limits already existed for exposure in workplaces. But three years after the storm, only California had issued such limits.

Industry groups like the American Chemistry Council have repeatedly challenged the science linking formaldehyde to cancer, a position championed by David Vitter, the Republican senator from Louisiana, who is a major recipient of chemical industry campaign contributions, and whom environmental groups have mockingly nicknamed “Senator Formaldehyde.”

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Formaldehyde in Laminate Flooring

In laminate flooring, formaldehyde is used as a bonding agent in the fiberboard (or other composite wood) core layer and may also be used in glues that bind layers together. Concerns were raised in March when certain laminate flooring imported from China was reported to contain levels of formaldehyde far exceeding the limit permitted by California.





Often made of melamine resin


Paper printed to resemble wood,

or a thin wood veneer


Layers may be bound using

formaldehyde-based glues


Fiberboard or other

composite, formed using

formaldehyde-based adhesives


Moisture-resistant vapor barrier

What is formaldehyde?

Formaldehyde is a common chemical used in many industrial and household products as an adhesive, bonding agent or preservative. It is classified as a volatile organic compound. The term volatile means that, at room temperature, formaldehyde will vaporize, or become a gas. Products made with formaldehyde tend to release this gas into the air. If breathed in large quantities, it may cause health problems.



Pressed-wood and composite wood products

Wallpaper and paints

Spray foam insulation used in construction

Commercial wood floor finishes

Crease-resistant fabrics

In cigarette smoke, or in the fumes from combustion of other materials, including wood, oil and gasoline.

Exposure to formaldehyde in sufficient amounts may cause eye, throat or skin irritation, allergic reactions, and respiratory problems like coughing, wheezing or asthma.

Long-term exposure to high levels has been associated with cancer in humans and laboratory animals.

Exposure to formaldehyde may affect some people more severely than others.

By 2010, public health advocates and some industry groups secured bipartisan support in Congress for legislation that ordered the E.P.A. to issue federal rules that largely mirrored California’s restrictions. At the time, concerns were rising over the growing number of lower-priced furniture imports from Asia that might include contaminated products, while also hurting sales of American-made products.

Maneuvering began almost immediately after the E.P.A. prepared draft rules to formally enact the new standards.

White House records show at least five meetings in mid-2012 with industry executives — kitchen cabinet makers, chemical manufacturers, furniture trade associations and their lobbyists, like Brock R. Landry, of the Venable law firm. These parties, along with Senator Vitter’s office, appealed to top administration officials, asking them to intervene to roll back the E.P.A. proposal.

The White House Office of Management and Budget, which reviews major federal regulations before they are adopted, apparently agreed. After the White House review, the E.P.A. “redlined” many of the estimates of the monetary benefits that would be gained by reductions in related health ailments, like asthma and fertility issues, documents reviewed by The New York Times show.

As a result, the estimated benefit of the proposed rule dropped to $48 million a year, from as much as $278 million a year. The much-reduced amount deeply weakened the agency’s justification for the sometimes costly new testing that would be required under the new rules, a federal official involved in the effort said.

“It’s a redlining blood bath,” said Lisa Heinzerling, a Georgetown University Law School professor and a former E.P.A. official, using the Washington phrase to describe when language is stricken from a proposed rule. “Almost the entire discussion of these potential benefits was excised.”

Senator Vitter’s staff was pleased.

“That’s a huge difference,” said Luke Bolar, a spokesman for Mr. Vitter, of the reduced estimated financial benefits, saying the change was “clearly highlighting more mismanagement” at the E.P.A.


The review’s outcome galvanized opponents in the furniture industry. They then targeted a provision that mandated new testing of laminated wood, a cheaper alternative to hardwood. (The California standard on which the law was based did not require such testing.)

But E.P.A. scientists had concluded that these laminate products — millions of which are sold annually in the United States — posed a particular risk. They said that when thin layers of wood, also known as laminate or veneer, are added to furniture or flooring in the final stages of manufacturing, the resulting product can generate dangerous levels of fumes from often-used formaldehyde-based glues.

Industry executives, outraged by what they considered an unnecessary and financially burdensome level of testing, turned every lever within reach to get the requirement removed. It would be particularly onerous, they argued, for small manufacturers that would have to repeatedly interrupt their work to do expensive new testing. The E.P.A. estimated that the expanded requirements for laminate products would cost the furniture industry tens of millions of dollars annually, while the industry said that the proposed rule over all would cost its 7,000 American manufacturing facilities over $200 million each year.

“A lot of people don’t seem to appreciate what a lot of these requirements do to a small operation,” said Dick Titus, executive vice president of the Kitchen Cabinet Manufacturers Association, whose members are predominantly small businesses. “A 10-person shop, for example, just really isn’t equipped to handle that type of thing.”

Becky Gillette wants strong regulation of formaldehyde. Credit Beth Hall for The New York Times

Big industry players also weighed in. Executives from companies including La-Z-Boy, Hooker Furniture and Ashley Furniture all flew to Washington for a series of meetings with the offices of lawmakers including House Speaker John Boehner, Republican of Ohio, and about a dozen other lawmakers, asking several of them to sign a letter prepared by the industry to press the E.P.A. to back down, according to an industry report describing the lobbying visit.

Within a matter of weeks, two letters — using nearly identical language — were sent by House and Senate lawmakers to the E.P.A. — with the industry group forwarding copies of the letters to the agency as well, and then posting them on its website.

The industry lobbyists also held their own meeting at E.P.A. headquarters, and they urged Jim Jones, who oversaw the rule-making process as the assistant administrator for the agency’s Office of Chemical Safety and Pollution Prevention, to visit a North Carolina furniture manufacturing plant. According to the trade group, Mr. Jones told them that the visit had “helped the agency shift its thinking” about the rules and how laminated products should be treated.

The resistance was particularly intense from lawmakers like Mr. Wicker of Mississippi, whose state is home to major manufacturing plants owned by Ashley Furniture Industries, the world’s largest furniture maker, and who is one of the biggest recipients in Congress of donations from the industry’s trade association. Asked if the political support played a role, a spokesman for Mr. Wicker replied: “Thousands of Mississippians depend on the furniture manufacturing industry for their livelihoods. Senator Wicker is committed to defending all Mississippians from government overreach.”

Individual companies like Ikea also intervened, as did the Chinese government, which claimed that the new rule would create a “great barrier” to the import of Chinese products because of higher costs.

Perhaps the most surprising objection came from Senator Boxer, of California, a longtime environmental advocate, whose office questioned why the E.P.A.’s rule went further than her home state’s in seeking testing on laminated products. “We did not advocate an outcome, other than safety,” her office said in a statement about why the senator raised concerns. “We said ‘Take a look to see if you have it right.’ ”

Safety advocates say that tighter restrictions — like the ones Ms. Boxer and Mr. Wicker, along with Representative Doris Matsui, a California Democrat, have questioned — are necessary, particularly for products coming from China, where items as varied as toys and Christmas lights have been found to violate American safety standards.

While Mr. Neltner, the environmental advocate who has been most involved in the review process, has been open to compromise, he has pressed the E.P.A. not to back down entirely, and to maintain a requirement that laminators verify that their products are safe.

An episode of CBS’s “60 Minutes” in March brought attention to the issue when it accused Lumber Liquidators, the discount flooring retailer, of selling laminate products with dangerous levels of formaldehyde. The company has disputed the show’s findings and test methods, maintaining that its products are safe.

“People think that just because Congress passed the legislation five years ago, the problem has been fixed,” said Becky Gillette, who then lived in coastal Mississippi, in the area hit by Hurricane Katrina, and was among the first to notice a pattern of complaints from people living in the trailers. “Real people’s faces and names come up in front of me when I think of the thousands of people who could get sick if this rule is not done right.”

An aide to Ms. Matsui rejected any suggestion that she was bending to industry pressure.

“From the beginning the public health has been our No. 1 concern,” said Kyle J. Victor, an aide to Ms. Matsui.

But further changes to the rule are likely, agency officials concede, as they say they are searching for a way to reduce the cost of complying with any final rule while maintaining public health goals. The question is just how radically the agency will revamp the testing requirement for laminated products — if it keeps it at all.

“It’s not a secret to anybody that is the most challenging issue,” said Mr. Jones, the E.P.A. official overseeing the process, adding that the health consequences from formaldehyde are real. “We have to reduce those exposures so that people can live healthy lives and not have to worry about being in their homes.”

The Uphill Battle to Better Regulate Formaldehyde

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