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Chinese steel in pressure piping
3

Chinese steel in pressure piping

Chinese steel in pressure piping

(OP)
Has anyone has had experience with chinese steel pipe for operating pressures of 150 PSI. ASTM A234?

RE: Chinese steel in pressure piping

ASTM A 234 should be for pipe fittings...

By the way, 150 psi is not a high operating pressure. If you have any specific problem on this operating pressure, please advise...

RE: Chinese steel in pressure piping

What are you looking for??? I beleive to meet standards for the material you need to destructive test 1 material for each heat, and then nde 10% of all material.

Did they not supply mill test reports?

RE: Chinese steel in pressure piping

(OP)
Yes, they supplied reports of every heat. We tested a number of the heats with good resuls. However, we did not test all of the heats. The client refused to accept the fittings installation because they had concerns that chines fittings were of inferior quality.
 

RE: Chinese steel in pressure piping

You have the certs showing the material is acceptable. If they don't want chinese steel for pressure containing parts, well that is what specifications are for.

If it wasn't in a spec or part of the original contract, you could offer to replace them at additional cost/time. But it doesn't sound like they have cause to reject.

RE: Chinese steel in pressure piping

Agreed with Gibson, there does not seem to be any reason to not accept the pipe....did they provide a list of manufactures to use? If not you can not simply say something is of inferior quality without proof, by signing the original contract without an specified manufacturers then you can buy the pipe anywhere as long as the test reports show that it meets the spec....any additional testing would be at the cost of the client.

RE: Chinese steel in pressure piping

On a lighter note....

One of the threads that rconner refers to involves that famous P91 "high energy piping" power plant disaster that killed three involving (longitudinal)seam welded pipe.

One of the poster's to that thread stated that:

"The Chinese Government has also banned Chinese made pipe for use in major power plant critical applications."

It is my understanding that, after many years of industry experience, and the development of Chinese Quality Control Stsandards and Design Specifications, the Chinese are now accepting thier own domestically produced P91 piping...

   

RE: Chinese steel in pressure piping

Still, for a little 'kumsha' [$$], your Chinese Certified Material Test Report can read anything you need it to read.  If you didn't make a better payoff of their QC, you literally have no idea what your material really is.  Client is correct, however if it was not in your Contract with them, they have to pay to upgrade to a 'safe' country of origin.  Look in the Contract for all referenced client specs.  You may have signed something that references a client spec that forbids Chinese junk.

RE: Chinese steel in pressure piping

An experience with some Chinese pipes:
Acceptable within tests and spec but terrible in handling and transportation by ships. They knew how to build it but didn't know (care) how to transport it. This had caused many damages to the external coating and edges of the internal lining.

More general perspective: Chinese stuff can be anywhere between a junk and super quality. Check what you buy and what you pay.

You didn't mention the diameter. This is important especially concerning the transportation.  

RE: Chinese steel in pressure piping

We prohibit the use of Chinese flanges and fittings at this time for the reasons stated by Duwe6 amongst others. When you find a CMTR which is incorrect per the materials specification, it is difficult to trust it or others when the supplier asks you, "What do you want it to state?"   

General comment: In terms of trusting a CMTR as full validation of the material recieved, I have found many a mixed steel whose markings matched those on the supporting CMTRs.  

RE: Chinese steel in pressure piping

If you roll this discussion back to 1960 and replace the word "China" with the word "Japan" it all holds true.  Back then "Made in Japan" was a sign of utter garbage made by an overworked and under trained subsistence-level work force recovering from the ravages of war.  10 years later people that had proscriptions against buying industrial equipment and supplies from Japan were starting to lose market share to people who noticed the change in value provided by the Japanese industries and had started preferentially buying their products.  10 years later, the gold standard for pipe came from Japan, and the U.S. mills were turning out utter garbage (5 years later the U.S. Steel industry cleaned up their act and started producing a competitive product again).

The point is that China is rapidly moving through the stages of development and it is a HUGE economy.  I'm confident that WaterPipe has it right--their products do range from junk to super quality.  In a few years we'll start to see the "usual" product from China being better than "acceptable".  Be really careful with "No Chinese Steel" policies because the stuff that was junk will be evolving every day with market forces.

David

RE: Chinese steel in pressure piping

Having done quality audits of pipe mills in China, Japan, etc; I have to put in 2 cents. A major factor is whether you are getting a few joints from a distributor, or the luxury of a mill run. For mill runs, you have (qualified) 3rd party witness in the mill ( I might "trust" a Japanese mill because management totally embraced "quality" /Deming). This must be defined in the PO.
For smaller orders, you will have less control. You send the 3rd party to the distributor, and keep records of who did what to you. I have had 3rd parties tell me the distributor looked through a file of mill certs until he found one that met requirements; then promised the pipe was from that heat. For CRITICAL small orders, you have to do NDE and physical tests, regardless of origin.

RE: Chinese steel in pressure piping

Even if you have third party inspection and after pipes/equipment has passed the inspection we have found that pipes/equipment will be repackaged/relabelled to be used on another project and you get what was not inspected.

Regards

athomas236

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