ASTM A369 Grade FP22
ASTM A369 Grade FP22
(OP)
Dear All,
In our spec. for VHS requirement (Press.=117 Barg, Temp.=519 deg. C), we need heavy wall thickness pipe Forged & Bored, BE, ASME B36.10M, ASTM A369 Grade FP22, with thickness and size :
* NPS 30" , thickness = 63.5 mm
* NPS 36" , thickness = 76.2 mm
There is one Bidder who was offering us an option as below :
* Pipe EFW, ASTM A691 Grade 2-1/4 Cr, Class 22 (welded pipe with sress relieved)with thickness tolerance +/- 0.3 mm.
Anybody can help me, is it technically acceptable or not ?
I have read the ASTM A691 standard. It clearly mentioned that thickness cover up to 75 mm only.
Is there any other requirement if we accept this offered material ?
Please give me suggestion and explanation.
Thanks and regards,
Denil
In our spec. for VHS requirement (Press.=117 Barg, Temp.=519 deg. C), we need heavy wall thickness pipe Forged & Bored, BE, ASME B36.10M, ASTM A369 Grade FP22, with thickness and size :
* NPS 30" , thickness = 63.5 mm
* NPS 36" , thickness = 76.2 mm
There is one Bidder who was offering us an option as below :
* Pipe EFW, ASTM A691 Grade 2-1/4 Cr, Class 22 (welded pipe with sress relieved)with thickness tolerance +/- 0.3 mm.
Anybody can help me, is it technically acceptable or not ?
I have read the ASTM A691 standard. It clearly mentioned that thickness cover up to 75 mm only.
Is there any other requirement if we accept this offered material ?
Please give me suggestion and explanation.
Thanks and regards,
Denil





RE: ASTM A369 Grade FP22
I would only use seam welded pipe if you are below the time dependent allowable stress values for this material. In this case, the service temperature should be below 482 deg C. Since your service temperature is 512 deg C, I would not recommend seam welded pipe.
Try A 335 Grade P22.
RE: ASTM A369 Grade FP22
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RE: ASTM A369 Grade FP22
I addition, by introducing a seam weld, you will need to monitor this pipe material for in-service creep damage over time. This cost must be added to your selection of using welded pipe.
ASME B&PV Code does not currently permit the use of seam welded pipe in construction. However, this will be changing with the introduction of hefty penalty factors to current allowable stresses. For this case, you might see a factor of 50% meaning the pipe will become twice as thick to provide for adequate creep design margin.
RE: ASTM A369 Grade FP22
Your suggestion and explanation are highly apreciated.
We would like not to accept of welded pipe option offered by that Bidder.
Thanks and regards,
Denil
RE: ASTM A369 Grade FP22
If the SA 691 option selected is only stress releif, then everything Meteng stated is correct, and a weld creep strength reduct factor of about 0.75 would need to be applied and longitudinal weld creep monitoring device be added.
There is to be presented a paper by a japanese author at this week's EPRI Fla confernece on advanced alloys that presents their lab results of the HAZ property restoration that occurs with N+T. I understand the ASME committees are under pressure to approve SA 691 for sect I and B31.1 service.