Investigation of surfacing technique for valve stem of spe cial valves in catalytic cracking devices

The working conditions of the valve stem surf ace of a special valve in the catalytic cracking devices are analyzed totally an d deeply and then the surfacing technique for the valve stem is designed and tes ted. It is shown that the service life of the valve stem can be improved doubly when the valve stem surface is treated with oxyacetylene flame spraying, so that the economic loss due to rush repairs of the devices can be eliminated.