P91 pipe failure in China

[athomas236]

For those of you that have an interest in P91, you may be interested in the following:

On 31 Oct 06 there was a failure in the main steam pipe at Huadian Datong Power Station in China. The failure occurred after the unit had been under going commissioning for a period of 6 weeks. The failure resulted in deaths and other injuries.

Main steam conditions: 2538psig and 1006F
Material: ASTM A335 P91 - 18inch, 1.693 ins thick (seamless)
Rupture was 35 inches long by 1.5 to 2 ins wide and 86 ins from nearest weld.

History of pipe material is still under investigation but preliminary reports suggest the pipe was counterfeit, that is made in China but marked as made in USA.

The Chinese goverment is conducting a formal investigation since pipe is reported to have been used in other plants in China. The use of Chinese made pipe for such critical applications has been banned.

It is thought that some suppliers in the US have placed orders with the mill producing this pipe.

I only learned about this 29 Jan 07 but if anyone has more upto date information, then please advise.

athomas236

 

[mizzoueng]

The story I saw on this was that it came from one of three mills. There are only 3 mills that make/sell P91 pipe, they did not give them name of the mill it came from.

Apparently they were in the testing phase of the boiler and were near full load when the pipe ruptured. I did read that they determined right away that is was conterfiet. It was said that it was common carbon steel that had its ends milled to match P91 and was smoothed/coated to look like P91, then they some how got ahold of P91 stamps and punched it.

The on-site engineer did not do a material test as they bought it from a trusted vendor, it looked like P91, was stamped P91, so s/he had no reason to believe it was not P91. Not until it was too late.

I guess when the pipe blew one or two guys were close and got killed when the steam hit them. I think 5 got 2nd and 3rd degree burns from the steam as well.

 

[metengr]

You might be interested to review this thread
thread330-172967

 

[athomas236]

Thanks metengr

athomas236