Tungsten carbide coating for Ball & Seat

[Iranna Shettar]

for Sour Sales Gas services, the below requirement is applicable, please clarify.

Ball Material is SS316L & A105 with weld overlay

Tungsten carbide coating is carried out on ball and seat surfaces to increase the hardness of the surfaces for wear
resistance.

want to know the above requirement is mandatory & where the requirement will be specified? as I did not notice in any of the specifications provided by client.

Regards
Iranna

 

[mk3223]

API and NACE MR0175 Codes specifies several material types with the hardness requirement of the valve trim design.
IMO, the manufacturer develops the process to fabricate the material with the testing procedure to meet this requirement. The tungsten carbide coating on the ball and seat of the valves is one of the manufacturing process.