Slam
Slam turns up in 2 fields: valves, telecom & it. Here is what it means to the people in each one.
Slam in valves
A check valve banging shut after flow has already reversed, sending a pressure surge through the line.
When a pump trips, flow decelerates and reverses; a heavy swing check that closes late gets driven onto its seat by the reverse flow and stops that flow instantly. The bang and pressure spike can break supports, valves and instruments. Fast-closing spring-assisted, nozzle or dual-plate checks reduce slam by shutting before the reverse flow builds.
"Check valve slam on pump trip is shaking the whole rack, swap it for a nozzle check and see if it settles down."
Slam in telecom & it
To switch a customer's telephone service provider without their authorization.
Slamming is the illegal practice of changing a subscriber's local or long-distance telephone service to a different carrier without the customer's explicit consent. Unscrupulous carriers historically used deceptive marketing or forged authorizations to hijack lines and charge inflated rates. Regulatory agencies strictly penalize carriers caught slamming.
"The client complained about a massive bill because some shady reseller slammed their trunk lines last month."