Cast SS Wedge vs Forged SS Wedge for gate valve

[Gio Grande]

Cast SS Wedge vs Forged SS Wedge for gate valve:

.5 to size 2 inch is solid wedge and 3 to 10 inch is Flexible wedge.

I am been offered Cast SS Wedge instead of Forged SS Wedge. I am thinking cast steel wont do well in water hammer cases

Please which is better Cast Stainless Steel Wedge vs Forged Stainless Steel Wedge for gate valve?

 

[Danlap]

Your question is quite general (no medium information, is this actuated or manually operated), therefore responds might be general as well.
Different between casting and forging mainly over residual microsegregation in the cast structure. This is more of corrosion resistance, I don’t think this relates to water hammer compatibility.

if this is manually operated, hence slower closing time, don’t think water hammer will be an issue.
If actuated, then do surge calculation to determine minimum closing time. If water hammer is not avoidable, then address/mitigate/reduce risk of water hammer first on upstream of the valve. Neither forged nor casted SS won’t be any good for frequent water hammering.
Trim material selection in this case wedge is predominantly determined by its medium and its corrosion rate. NACE or not? Brackish or not? Etc.

In our company, it doesn’t really matter e.g. A182F316 or A351CF8M as long as carbon content is not exceed 0.03% by mass. Some exception might up to 0.08% with stabilization requirement.
Forged is more preferred but not due to water hammer issue.