WOG and ASNI Class Rating

[Sid89]

I have a 3-piece valve whose center body is rated at 2250WOG while the end-caps are rated for ANSI Class 600. My question is would the end-caps rating limit the overall pressure/temperature rating of the valve? Since 2250WOG represents 2250psi at ambient temperature while class 600 is good only up to 1440psi at temperatures below 100deg.F.
Or
Can we say that the Class 600 end-caps will hold 2250psi pressure at ambient temperature?

 

[LittleInch]

Well first off it's ASME class 600 not ANSI (or ASNI)

Second what is an end cap on a valve? Do you mean a flange?

Assuming you mean a flange then yes, the lowest rated pressure component sets the limit for the item.

The rating of the flange depends on the material - see ASME B16.5 for your particular material and temperature pressure rating, but it's probably around 1450-1500 psi at that temperature.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[bcd]

It is a 3-piece ball valve. Since you mention 2250 WOG, I am thinking this is a NPS 2 or smaller ball valve. If so, the end caps are usually threaded, socket weld or butt weld. Sometimes are made with flanged ends, but not very often.

The lowest rated part of the assembly dictates the overall rating. With the end caps (and most likely the body bolting as well) being rated for ASME Class 600, then the Class 600 rating for the material is the max. However, carefully check the internal ratings. Plastic seats and seals may limit the shut-off pressure rating to an even lower value.