carbon steel bolts in stainless steel ball valve

[faridg22]

Hello every body

ASTM A-351 2 ball valve with bonnet bolted with carbon steel bolts is that normal, will the stainless steel body of the valve will affected or contaminated by corrosion

Regards,
Farid

 

[TomDOT]

Depends on the conditions. If the valve is in a controlled (indoor type) environment and the bolts are not exposed to the fluid, I wouldn't expect an issue.

Conversely, if the valve is outside in an oceanside environment, I would expect accelerated galvanic corrosion of the bolts. Staining would certainly flow over the stainless body.

 

[faridg22]

many thanks

 

[pradipgoswami]

Advice is to stay away from Carbon Steel bolts as long term and better engineering practice.
How do you ensure that any galvanic cell does not get established(between bolts and valve body)even in the indoor environment, especially when valves are meant to work in wet environments.

How can one avoid corrosion during any wetlay up or fluid stagnation?

Considering the price you pay for the valves, the cost of switching to S.S bolts would be very minimal.

Thanks

Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario, Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299

 

[TomDOT]

Agreed. Unless there are galling concerns, stainless bolts are the better choice.

 

[faridg22]

thanks every body it is very useful

As per the certificate delivered from the vendor, it is shows nuts are in stainless steel(A194 GR8), but unfortunately it is not the case.nuts are in carbon steel and rusrt starts to build-up
i think i will reject these valves


Regards,
Farid