ESD Ball Valve material
ESD Ball Valve material
(OP)
Ball Valve material
In ongoing project we are procuring ESD ball valves of various class ratings i.e. 300 onwards up to 1500#. Client specification for ball material is ASTM A182 F316L or A351 –CF8M. Vendor from whom we are procuring these valves is unable to give this ball material for class 600# and above. Vendor says for class 600# and above SS is soft. Argument given by vendor is during hydro test pressure (1, 5 times) SS 316 may not withstand hydro test pressure. (220 bar hydro test pressure or more for class 600# and above). I want to know is it really a fact that for class 600# and above SS 316 can not be used as a ball material? Somehow, I am not convinced with this vendor argument and trying to go through various standards to check his claim. Want to know opinion from this forum. thanks.
In ongoing project we are procuring ESD ball valves of various class ratings i.e. 300 onwards up to 1500#. Client specification for ball material is ASTM A182 F316L or A351 –CF8M. Vendor from whom we are procuring these valves is unable to give this ball material for class 600# and above. Vendor says for class 600# and above SS is soft. Argument given by vendor is during hydro test pressure (1, 5 times) SS 316 may not withstand hydro test pressure. (220 bar hydro test pressure or more for class 600# and above). I want to know is it really a fact that for class 600# and above SS 316 can not be used as a ball material? Somehow, I am not convinced with this vendor argument and trying to go through various standards to check his claim. Want to know opinion from this forum. thanks.





RE: ESD Ball Valve material
It is not tht the material is "soft". The modulus of elasticity is essentially the same as other steels, so until the stress exceeds the material yield, the amount of deformation is roughly the same. Unless it is strain hardened, 316 / CF8M has a lower yield strength than 400 series steels that are commonly used for high pressure valve trim parts such as balls and stems.
RE: ESD Ball Valve material
I think their concern might be abrasion on the ball in a dirty service when it rotates from open to closed or vice versa, causing it to lose its ability to seal over time.