P91 Pipe Failures in China

P91 Pipe Failures in China


(04-Jan-2007) - Please be aware that failures of P91 (high strength 9 Chromium - 1 Molybdenum) piping material have been reported in China.  According to the sources,

• these failures have resulted in 6 fatalities
• the manufacturing quality of the pipework is suspect and the failures occurred within 8 weeks of being placed in to service
• the P91 pipe is being referred to as "fake pipe"
• the failures have occurred only in China
• the pipe was manufactured in China
• some of it was marked as having been manufactured in Houston, Texas, but it was not
• the pipe was hot expanded, which caused cracking, and failed after 6 to 8 weeks of service
• some of this pipe may have been shipped to the US and elsewhere

Attached below are photos.

There is not much more detail on the problem at this time.  The purpose of this news story is to raise awareness of the potential for counterfeit P91 material in our global market.  This material is typically used in power plants and power facilities.  It is suggested that anyone purchasing this piping material for their project validate its source.  Perform Positive Material Identification (PMI) and contact your supplier and the mill or manufacturer and ask for validation by markings, heat number, size and quantity.  Do not trust Material Test Report (MTR) documentation only.    

Update (08-Jan-2007) - Additional information about this alert is as follows:

• The failure occurred in ASTM A335 P91 - 18" OD, 1.693 wall seamless pipe (that is believed to be counterfeit).  The pipe was operating at 2538 psig and 1006°F.
• The failure occurred in a vertical section and was 86" from the nearest weld.  The longitudinal rupture was 35" by 1.5" to 2".
• It is believed that pipe was billeted by mill in China who sold to Chinese firm that extruded and heat treated the pipe.  The pipe was then sold again to another firm who polished the OD and sized the ends.
• A formal investigation is being conducted by the Chinese government.