316H SS forged valve vs cast valve

[jtseng123]

All materail experts, I got a deviation request form supplier, pelase help to see if that is accepatble or not:

Our valve supplier is proposing the cast version of 316H (Material Designation A351-CF8M high temperature casting material, which will meet the H grade specified) in lieu of F316H forging for the automated on-off valve bodies.
Our Piping Material Class Specification states 316H body required for valves in this severe high-temp service, but does not specify whether or not cast bodies are acceptable.
The supplier states A351-CF8M cast valve body is what is currently available to meet our delivery schedule.

Will that be acceptable for the cast valve body ? This is for 1450 degF/ 60 psig service with catalyst flowing that erosion is the concern.

 

[metengr]

jtseng123;
Yes, the cast version of this alloy should be acceptable. Since you did not mention the type of service, I am providing the following Supplementary Requirements for your consideration (my recommendation and not a requirement);

S5 Radiographic Inspection
S6 Liquid Penetrant Inspection
S11.1 Post Weld Solution Treatment for weld repair (if performed).

 

[jtseng123]

Very thanks metengr.
This is for fluidized catalytic cracking unit( FCCU) that catalyst is used to break down the crude oil. In this valve, the hot catalyst is flowing through, and the entire piping system is per B31.3 code.
For the 3S supplements you are recommending, what is the code ?
Shall I add UT to check voids and lamination ? if yes, what S- supplement shall I specify ?

 

[metengr]

jtseng123;
The supplements I mentioned are in the ASTM material specification - ASTM A 351 at the end. You do not need a UT, if RT is specified by Supplement S5.

A word of caution, make sure you have the acceptance critria for the RT and Liquid PT examinations. Also, make sure the NDT personnel performing the examinations are certified to Level II ASNT.

 

[jtseng123]

That helps me alot, many thanks.