From the initials of Astra Română, the name of a petroleum refiner in Romania + gaz.
cit. https://en.wiktionary.org/wiki/aragaz
(refers also to that kind of butane gaz itself)

aragaz, n.
nominativ-acuzativ
sg. aragaz aragazul
pl. aragazuri aragazurile

genitiv-dativ
sg. aragaz aragazului
pl. aragazuri aragazurilor