Hight Strength Flange Bolts
Hight Strength Flange Bolts
(OP)
I have an ASME VIII low temperature / low pressure applications (275 psig @ 140 F). I have a custom flange design and the number of bolts and size is critical.
I am currently using 1/2" 193-B7 studs and am asking if their is any other ASME acceptable stud material with a higher strength (yield and tensile).
Thank you in advance for your help. This is something I would need in the very near future for this one-time application.
I am currently using 1/2" 193-B7 studs and am asking if their is any other ASME acceptable stud material with a higher strength (yield and tensile).
Thank you in advance for your help. This is something I would need in the very near future for this one-time application.





RE: Hight Strength Flange Bolts
Do you have access to Sec II, Part D by chance? If so, see Table 3. You really need to select based on your service, any limitations noted in Table 3 and commercial considerations.
I have used SA-354 BD (150 ksi min tensile) once before.
Regards,
Mike
RE: Hight Strength Flange Bolts
At 275 psi, generally B7 bolts are suitable for a variety of flange and gasket combinations, especially for class 300 and above flanges, so I would look into off the shelf components to suit your needs.
RE: Hight Strength Flange Bolts
You should be using a Category II Standard fastener (i.e. Sweet application - Cold Temperature), something like ASTM A320 L7 Stud with ASTM A194 4/7-S4 Heavy Hex Nut.
The Category II NACE fastener is ASTM A320-L7M with ASTM A194 7M-S4 Heavy Hex Nut. You could theoretically use this low temperature NACE faster(s) for a low temperature standard application, BUT NOT the reverse.
Be careful with fastener selection, your initial choice is only good for a Standard Service Category I application, which is not low temperature. B7 studs are not Notch Toughness and therefore, restricted for use under the spirit of the code.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: Hight Strength Flange Bolts
XM-19 (austenitic Fe-Cr-Ni-Mn alloy)
17-4 PH (martensitic Fe-Cr-Ni-Cu alloy)
B22 (4140 steel)
718 (nickel alloy)
SA 574 (4140 steel)