ASTM A 354 Grade BD - NACE MR 0175 3

[robertm1]

HI
If bolting materials that meet the specification of ASTM A 354 Grade BD meet the requirements of NACE MR 0175.
Is it correct to use them for API 6A flanges (size 2 1/16" and 3 1/16") for sour environment.
Thank you

 

[gr2vessels]

robert,
The post doesn't make much sense;- are you stating or asking if the A354 BD bolts meet the requirements of NACE MR 0175.
Also, the NACE MR 0175 gives you a clear definition of the 'sour environment', with regards to H2S concentration, temperature, etc. Part 2, Section 7 of the standard gives you the H2S partial pressure and pH limitations for use of carbon and low alloy steels in upstream O&G production. Remember to check the material hardness limitations, since the A354 bolts have a very high hardness, which probably exceeds the NACE limitations.
BTW, are your bolts submerged in liquid containing H2S?
As for the second question, the A354 bolts are typically used for anchor bolts, not for high pressure API 6A flanges.
Cheers.
gr2vessels

 

[TVP]

Robert,

ASTM A 354 Grade BD fasteners are not acceptable for sour service. These are high strength fasteners quenched and tempered to 31-39 HRC. NACE MR 0175 specifies a maximum of 22 HRC for bolting. Acceptable fasteners are ASTM A 193 Grade B7M, 22 HRC maximum.