Relief valve and Spill valve

Relief valve noun - 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.

Spill valve and relief valve are semantically related. In some cases you can use "Spill valve" instead a noun phrase "Relief valve".

Relief valve and spill valve are semantically related. You can use "Relief valve" instead a noun phrase "Spill valve".