Seat
Seat turns up in 2 fields: valves, aviation. Here is what it means to the people in each one.
Seat in valves
The surface inside a valve that the closure member presses against to stop flow.
Seats may be machined into the body, hardfaced with a cobalt or nickel alloy, threaded or welded in as a renewable ring, or made of a polymer such as PTFE, reinforced PTFE or PEEK in soft-seated valves. Seat condition decides shutoff tightness, and seat leakage is measured against a class or an allowable rate during the seat test. In ball valves, the seats are separate rings that the ball rotates against.
"We lapped the seat on that globe and it's still passing, the steam cut must be too deep to lap out."
SEAT in aviation
A single-engine air tanker is a small aircraft modified to drop water or fire retardant.
The Single-Engine Air Tanker (SEAT) is an agricultural-style aircraft repurposed for aerial firefighting. Because of their small size and maneuverability, these planes can operate from dirt strips close to a fire line and drop pinpoint loads of retardant in tight canyons.
"Dispatch is sending two SEATs to hit the ridge before the heavy tankers arrive."