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US 5,291,913 AGranted
Fluid valve having a zirconium oxide coated valve disc
AssigneeWestinghouse Electric Corp.
InventorsJames C. Hill, David W. Holt
Life of this patent
Estimating the term…
Abstract
A fluid valve has a valve body with a valve seat for receiving a valve disc to close the valve. The valve seat is iron or steel. The valve disc is made of zirconium and has a zirconium oxide layer on disc surface which seats against the valve seat when the valve is closed. The valve has remained in a corrosive service for over six months where the original iron valves not having an oxide coated zirconium disc only lasted a few days.
Claims5
A fluid valve, comprising:
- a valve body having a valve seat for receiving a valve disc to close the valve, the valve seat comprised of a material selected from the group iron and steel;
- a zirconium valve disc having a zirconium oxide layer, which layer seats against the valve seat when the valve is closed.
A process for making a valve, comprising the steps of:
- soaking a zirconium disc having a surface in air at a temperature of from about 950.degree. F. to about 1250.degree. F. for at least about five (5) minutes to form a black oxide layer having a thickness of at least about five (5) ten-thousandths of an inch on the surface of the disc;
- and
- fitting the oxidized surface against a valve seat comprised of a material selected from the groups consisting of iron and steel of a valve body without surface treating the zirconium oxide layer.
Dependencies are inferred from the claim text.