A valve left barely open or not quite seated forces fluid through a narrow slit at high speed, especially with steam or flashing liquid. The jet cuts fine channels across the seat and disc, which then pass even more fluid, so the damage feeds itself. It is a common fate of gate valves used for throttling and of seats that close on scale or weld slag.
Pulled the bypass globe and the seat is wire drawn, they've been using it to throttle steam for a year.
Also heard as
- wiredrawing
- steam cutting
- seat cutting
Related terms
Seat
The surface inside a valve that the closure member presses against to stop flow.
Passing
Leaking through the seat while closed, so fluid still gets past a valve that is supposed to be shut.
Throttle
To hold a valve partly open on purpose to restrict and regulate flow or pressure.
Gate valve
A multi-turn isolation valve that lifts a flat or wedge-shaped gate clear of the flow path to open.