relief valve vs escape cock

relief valve and escape cock both are nouns.

Word	Noun	Adjective	Verb	Adverb
relief valve	Yes	No	No	No
escape cock	Yes	No	No	No

As nouns, relief valve and escape cock are synonyms defined as:

relief valve and escape cock: 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

Other synonyms of relief valve include escape, escape valve, safety valve.

relief valve (noun)	escape cock (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	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