Bending P91 small bore pipe
Bending P91 small bore pipe
(OP)
I am presently on a project in Mexico and the HRSG supplier has supplied straight run pipe (small bore), P11, P22 and P91. I have read some of your forums and have been in the industry for 30 years as an OEM rep, but have never used or have done any bending in the field. I guess I would like some guidance, procedures and people that are available to do this and are good at it. I know Shaw Group does some, but there must be others? We have some 2"sch 160 which is pretty tricky, so please forward me some info if you have the time.
Best Regards
Douglas
Best Regards
Douglas





RE: Bending P91 small bore pipe
I know of one additional pipe bending shop located in Duluth MN called BendTec. They are excellent at handling induction bending of heavy wall (large or small bore) pipe material, including P91. This material must be treated with extreme care otherwise you will have premature failure in service. BendTec can also handle P11 and P22 material with no problems.
RE: Bending P91 small bore pipe
We found that there are many small Mom + Pop pipe bending shops that do not realize this is a requirement for P91 piping. The reason for this requirement is that if you inductively heat only the zone that is being bent to 1900 F, there are adjoining zones that will be heated to only 1400 F- 1600F, and those zones will be overtempered and have much lower creep life than assumed by ASME code. To elimiante this issue, the entire pipe length that might have been overtempered will need a N+T.
When I say "requirement", I do not mean that ASME currently requires this directly, although itis being considered to be added as a code requirement. It is an implied requirement based on a liberal reading of the ASTM SA335 specification - any fabrication operation on a sa335 pipe should leave the fabricated component wit the same properties as the supplied sa335 pipe.
RE: Bending P91 small bore pipe
Regards
Douglas
RE: Bending P91 small bore pipe
Regards
Douglas
RE: Bending P91 small bore pipe
Sorry!
RE: Bending P91 small bore pipe
If you have any contacts there, check with them, although the question has already been adequately answered in this thread. I recommend this just for reinforcement, if you need it to justify the costs of doing it right.
rmw