what material is this? is it coated?

[mbelly84]

hello, please take a look at the attached picture.
this cap is used as a mechanical stop in lever operated ball valves (it's got no "structural" duty as it's not subject to loads)
seems clear to me that's a casting (CS or cast iron) but i'm not sure if the material is also coated in some way, or just oxidized by atmosphere?
thanks for your help
marco
valve engineer

 

[metengr]

You really need to have a bill of material for the valve. Visual ain't going to do it. Check the model number of the ball valve and see what other similar valve models are close for material.

 

[mbelly84]

i looked at it, unfortunately the cap is not on the BOM (probably because it's a loose item)

i'm waiting for an answer from factory but i was curious to know your opinions!

 

[tbuelna]

From the picture it looks like the cap is cast and machined. But even though there is some small amount of surface rust present on the part, I'd speculate that it might be made from something like a Ni-resist cast iron alloy.