Choke valve Plug and stem

[CarlosEstinos]

Hello all,

I am reverse engineering a Choke valve plug and stem. The component in question has a solid Tungsten carbide tip(Plug) . Out of interest how is such a component manufactured as the rest of the stem is stainless steal. I have attached a picture for reference.

I am considering having the new stem and plug Tungsten carbide coated as opposed to being solid . The thickness would be around 5/1000" .

Is there any consensus on whether this would be acceptable? I am little unsure on the flow medium at this moment, but any feedback on this subject would be gracefully received.

Regards

Carlos

 

[MikeHalloran]

The tip is probably made in the shape of a solid cylinder with a pointed end, like a crayon, ground from sintered billet, and crimped into a cylindrical recess in the end of the shank. ... which may be the only reasonable way to make it.

Tungsten carbide is sort of a powdered composite product, comprising fine grains of WC sintered in a binder like cobalt. AFAIK, it can't be, e.g. electroplated or electroformed or supplied as formable sheet. I think it can be metal-sprayed, but I wouldn't expect that finish to be as durable as what I think a choke valve plug needs.



Mike Halloran
Pembroke Pines, FL, USA

 

[gerhardl]

With reference to Mike Hallorans sensible answer: When reengineerin something it is always a question of comparing cost, lifetime and quality with suitabillity for the application if you are changing anything.

Your photo (a bit unclear) seems to show little wear and damage to the existing (used?) plug. Any reason to change material and specification or difficulties getting materials and machining with Mikes' suggestion? Any other problems not mentioned?

 

[bingbingwang]

5/1000" tungsten carbid i think is just good for anti-wearing (mechanical between two surfaces), it is not good enough for anti-cavitation. choke valves always use solid piece of carbid as a sleeve or plug coating for anti-cavitation/erosion-corrosion problems. it is welded on the plug ??? not very sure..... but i know stellite is solid piece welded on the plug tip.
better ask the manufacture of the valves.


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