Valve ball surface treatment
Valve ball surface treatment
(OP)
I have a large number of metal seated ball valves (ranging from 50mm to 350mm in the digester section of a pulp mill. Product is highly corrosive sulphide black liquor and So2 gas at a ph of 1.5. I was hoping someone could offer some advice on the most cost-effective method of hardfacing the balls. We currently use either CG8M parent material with a hardchrome or stellite surface treatment or polished solid stellite balls. The problem arises when balls need to be refurbished after the surface is damaged. The solid stellite is not a problem but is extremely expensive. On the other balls we've tried re-chroming as well as stellite weld overlays without much success to the point where we just grind the chrome off and use soft PTFE seats (soft seats are liable to 'wiping'). I would imagine the best method would be some sort of parent material heat treatment but i'm worried about the effect on corrosion resistance. We are also in the process of looking at elctroless nickel plating. I'd appreciate it if anyone's got any good ideas.





RE: Valve ball surface treatment
RE: Valve ball surface treatment
RE: Valve ball surface treatment
RE: Valve ball surface treatment
Here is one company that does this work.
http://www.dkmachine.com/Default.htm
RE: Valve ball surface treatment
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