water hammer vs bang

water hammer and bang both are nouns.

Word	Noun	Adjective	Verb	Adverb
water hammer	Yes	No	No	No
bang	Yes	No	Yes	Yes

As nouns, bang is a hypernym of water hammer; that is, bang is a word with a broader meaning than water hammer:

Other hypernyms of water hammer include bam, blast, clap, eruption.

water hammer (noun)	bang (noun)
the banging sound of steam in pipes	a conspicuous success
	a border of hair that is cut short and hangs across the forehead
	a sudden very loud noise
	a vigorous blow
	the swift release of a store of affective force

water hammer (verb)	bang (verb)
	strike violently
	close violently
	leap, jerk, bang
	have sexual intercourse with
	move noisily
	to produce a sharp often metallic explosive or percussive sound

water hammer (adverb)	bang (adverb)
	directly