This is the 11103rd most frequent Polish word.
gazowych
"Gazowych" means "gas-related" or "pertaining to gas."
Here, 'gazowych' is used as an adjective describing the noun 'piecyki', indicating that these heaters are powered by gas.
Podłączyliśmy piecyki gazowych wczoraj.
We connected the gas heaters yesterday.
In this sentence, 'gazowych' describes 'zaworów', highlighting that these valves are part of a gas system.
Regulacja zaworów gazowych jest bardzo delikatna.
The adjustment of the gas valves is very delicate.
'Gazowych' functions as an adjective for 'rurach', specifying that the pipes in question are used for transporting gas.