Use AQUA PLUMB, 3127Y, 1/2" x 260", Yellow, P.T.F.E. Gas Line Thread Tape for ferrous and non-ferrous fittings 4-mil. thick teflon tape can be used for connections in gas pipelines, cylinders and containers. Suited for all threaded connections involving gas line installations for natural gas, propane, butane and/or water, oil and chemicals. Withstands up to 10,000 PSI.