WCB Carbon Steel vs SS316 for Steam Application

[Donskie]

Hi all. Please help me decide which material is ideal for steam application at high pressures and temperatures, WCB Carbon Steel or SS316? I will be using a triple eccentric butterfly valve @ 8" in size and ANSI600.

Thank you all in advance for your infos.

 

[kany]

Donskie,

Butterfly valves are very-cost effective compared to alternate valve choices,offers high cycle life but actually they are not suitable enough for high pressure steam services. This is the very common disadvantage of these valve types.

I cant tell you the exact type without knowing at what temp/pressure and for which function valves will be used(starting/stopping the flow,regulating, preventing back flow etc.)

But based upon the material choice, it is more suitable to use cast iron ( approx. up to 450 F at 250 psi ). Of course you can also use ductile iron and s.s but your information is general. This is all I have.

Cheers

 

[kany]

BTW please review ASME B31.3 para K307 ( Valves & Specialty Components)

Cheers

 

[kany]

Actually check the whole chapter IX.. Sorry for too many replies

Cheers

 

[MisterDonut]

A triple-offset metal-seated butterfly valve can be a good choice for steam. Stainless is better for temperatures above 800ºF.You are more likely to see CF8M stainless for the body material than 316.

 

[MJCronin]

What are your "high pressures and temperatures" ?

Above 775F, the piping material of choice is chrome-moly steel, not 316SS. Typically this would be something like A335-P22 ( 2-1/4 CR - 1 MO).

Much higher temperatures get you into austenitic stainless materials, although there are other choices besides 316.

Regards