Debasis For catalyst dust with abrasive particles , WC coating with higher wear and heat resistance than Stellite or Cr coating will be better. Before that, why stellite coating failed and at what temp, velocity and throttling conditions in ball valve service in catalyst dust ? Please examine and do a failure analysis on this independently before only thinking of WC carbide coating. WC coating requires careful preparation and also degree of success depends on the particle size for getting higher wear resistance and at higher temperature. From hydrogen damage mechanism, WC coating with have better resistance. Hope this helps C.V.Srinivasan Nishi Engineers Pvt Ltd India July 15, 2008 E-mail: nishi@vsnl.com] >Valves ( Plug or Ball ) used in catalyst section of H-Oil >unit Catalyst lines sufffers from passing due to wear of >seat ring and ball. Stelliting has not proved to be a >solution. Even chromium carbide also seen to fail . > >Any one has any operating experience of using high velocity >oxyfuel coating of tungsten carbide coating and its >performances ? >Pl. share > >It is also been discussed that tungsten carbide coating is >resistant to hydrogen damage compared to Chromium carbide >coating. Pl. coment > >regards