It is water. A copper gas line is a different diameter then a water line is, so the water valve compression fitting will not seal on a gas line.
It is also a different kind of copper line. It is type G, K or L and must meet the standards of ASTM. Like I said you cannot assume anything because you make A a s s out of u and me.
Of course you are assuming it was done with the right copper in the first place
It’s water. Gas valves are threaded and have 1/4 turn shut offs. Tape is because home owner dosn’t know his fitting types.
Key word here is Owner!
This valve turned out to be a water valve. I returned to inspect after the bank winterized the house by turning on gas and repairing water service piping. I took the chance of briefly turning on the water service to the house and water came out of this valve, which was open. Go figure…
Good to hear!