A193 B7 REPLACING A193 B7M
A193 B7 REPLACING A193 B7M
(OP)
CAN WE USE A193 B7 REPLACE A193 B7M?
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A193 B7 REPLACING A193 B7M
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RE: A193 B7 REPLACING A193 B7M
RE: A193 B7 REPLACING A193 B7M
RE: A193 B7 REPLACING A193 B7M
RE: A193 B7 REPLACING A193 B7M
RE: A193 B7 REPLACING A193 B7M
Do you know why the bolts failed? Service conditions? Correctly HT'd B7 bolts are resistant to SCC in all but the most severe conditions.
RE: A193 B7 REPLACING A193 B7M
Bolts were in H2S/amine service.
RE: A193 B7 REPLACING A193 B7M
RE: A193 B7 REPLACING A193 B7M
The grade "B7M" was created to provide resistance to SCC and has been specified for use in "Sour" service for at least 3 decades.
RE: A193 B7 REPLACING A193 B7M
RE: A193 B7 REPLACING A193 B7M
I believe that you have the same comment.
Please clarify more about the service environment. Normally piping stud bolts will not directly contact to H2S/amine in the pipe. What is the reason to select bolt B7M instead of B7. If the adjacent pipes contain other non-corrosive fluids, should we select B7M because of in the sour service area?
In our plant, we also use B7M for H2S/amine service piping. However, sometimes the maintenance people replace them with B7. Should we worry for external bolting?
RE: A193 B7 REPLACING A193 B7M
If you are able to perform Rc tests on all B7 replacement bolts and select only the softer ones, that might work too.
RE: A193 B7 REPLACING A193 B7M
Please refer the following code and standard.
1. NACE MR 0175, Section 6 Bolting.
2. ASME Section VIII Div.1 Fig.UCS 66, General Note (e)
ThomasEun