API 610 Pump - Reduced Hardness Materials Req'd (5.12.1.12) 1

[Jackpang]

I am working on API 610 Data Sheet.

Does anyone know the criteria to determine if Reduced Hardness Materials are necessary? (Refer API 610 - 10th Edition, 5.12.1.12)

Low Temperature?
Sour Service?

Thanks,

Jack

 

[mk3223]

the hardness requirement for the pump is for the process containing sour H2S as specified in the section. It is per NACE standard because of the H2S stress corrosion cracking on hard steel.

 

[Jackpang]

It is sour H2S related. However, I am not clear what is the criteria to specify. For example, what concentration of H2S with even trace amount of water need such requirements? 50ppm, 100ppm...?

Thanks,

 

[SJones]

ISO 15156 (NACE MR0175) clearly defines when special requirements are to be applied for H2S service. If you are struggling with a liquid full system, take the partial pressure of H2S in the gas phase that was last in contact with the liquid.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/