Rupture Pin Relief Valve

relief valve
safety valve: a valve in a container in which pressure can build up (as a steam boiler); it opens automatically when the pressure reaches a dangerous level
Used at the discharge of a positive displacement pump. An adjustable, spring-loaded valve opens when a preset pressure is reached. Used to prevent excessive pressure buildup that could damage the pump or motor.
The relief valve (RV) is a type of valve used to control or limit the pressure in a system or vessel which can build up by a process upset, instrument or equipment failure, or fire.

rupture
(esp. of a pipe, a vessel, or a bodily part such as an organ or membrane) Break or burst suddenly
Suffer such a bursting of (a bodily part)
state of being torn or burst open
tear: separate or cause to separate abruptly; "The rope snapped"; "tear the paper"
a personal or social separation (as between opposing factions); "they hoped to avoid a break in relations"
Cause to break or burst suddenly and completely

pin
A thin piece of metal with a sharp point at one end and a round head at the other, used esp. for fastening pieces of cloth
trap: to hold fast or prevent from moving; "The child was pinned under the fallen tree"
attach or fasten with pins or as if with pins; "pin the needle to the shirt". "pin the blame on the innocent man"
A small piece of metal or wood for fastening or attaching things, in particular
a piece of jewelry that is pinned onto the wearer's garment
A small brooch or badge