Plumbing Fittings Question:

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In WA State gas unions are not allowed inside buildings. There are left and right hand couplings and nipples that take the place of unions. No sealant is required on unions faces - the seal is made by the beveled male/female surfaces. Also do not use regular teflon tape. There is a separate type of tape for gas. Really, I think TU555 is the best sealant.