| 摘要 |
<p>A valve, such as a butterfly valve having an offset closure vane and a thru shaft for operating the vane in the flow passage of the body, has all exposed and/or potentially vulnerable metal surfaces encapsulated in a corrosion resistant polymeric plastic coating. By extending the coating uninterrupted from the flow passage through the shaft bore and sizing the bore coating to within controlled tolerances, overall corrosion protection of the valve is substantially enhanced while enabling the coating per se to function as a bearing surface for the operator shaft.</p> |
