Spade
Spade turns up in 2 fields: valves, electricians. Here is what it means to the people in each one.
Spade in valves
A solid blank plate with a handle, slipped between flanges to positively isolate a line.
A spade is a single solid blind, usually with a handle stamped with its size and class so it is visible from outside the joint. Spading a line means spreading the flanges, inserting the spade with new gaskets, and bolting up. It gives isolation that does not depend on any valve seat, which is why permits for vessel entry and hot work call for spades or spectacle blinds.
"Spade the inlet and outlet before anybody goes in that drum, valves don't count for entry isolation."
Spade in electricians
A flat, U-shaped metal wire terminal designed to slide under a screw head.
A crimp-on or solder-on wire connector featuring a flat, forked blade. It allows a conductor to be secured to a terminal block or device screw without fully removing the fastener. Electricians use them for low-voltage controls and grounding connections where quick modifications might be needed.
"Crimp a spade on that ground wire so you can slip it right under the green screw."