gasometer vs storage tank

gasometer and storage tank both are nouns.

Word	Noun	Adjective	Verb	Adverb
gasometer	Yes	No	No	No
storage tank	Yes	No	No	No

As nouns, storage tank is a hypernym of gasometer; that is, storage tank is a word with a broader meaning than gasometer:

gasometer: a large gas-tight spherical or cylindrical tank for holding gas to be used as fuel
storage tank: a large (usually metallic) vessel for holding gases or liquids

Other hypernyms of gasometer include tank.

gasometer (noun)	storage tank (noun)
a large gas-tight spherical or cylindrical tank for holding gas to be used as fuel	a large (usually metallic) vessel for holding gases or liquids
a meter for measuring the amount of gas flowing through a particular pipe