blow gas vs blowing gas

blow gas and blowing gas both are nouns.

Word	Noun	Adjective	Verb	Adverb
blow gas	Yes	No	No	No
blowing gas	Yes	No	No	No

As nouns, blow gas and blowing gas are synonyms defined as:

blow gas and blowing gas: the gas leaving a generator during a blow period

blow gas (noun)	blowing gas (noun)
the gas leaving a generator during a blow period	the gas leaving a generator during a blow period