drain valve

drain valve

[′drān ‚valv] (chemical engineering) A valve used to drain off material that has separated from a fluid or gas stream, or one used to empty a process line, vessel, or storage tank.

drain valve

i. A valve at the bottom of a combustion chamber. When the engine shuts down, these valves open and prevent an accumulation of fuel in the combustion chamber. Also occurs after a false start.
ii. A valve at the bottom of any tank through which fluid is drained out.