Can we accept Stellite coating on valves seat and body internals for carbon steel and SS Valves all the time? Is there any limitation to use of these coatings on valves for certain situations ??
It depends on the specific service application. For steam service, Stellite hardfacing is routinely done and has a good track record for seats. For other service conditions, other hardfacing alloys may be more appropriate.
The coating will not be the limiting factor.
Other than adding excess cost there is no reason not to use it.
The real concern is the base metal under it.
It needs to be fully corrosion resistant in your service.
The Stellite will add erosion and erosion/corrosion resistance, but you still need to back it with the right material.