CNG Tank Regulator Connection

[shanagolden]

Every year or so I have changed my CNG tank without issue until this year when I connected the new filled tank, I can't seem to get a good seal. I tighten her up like I have in past and open the gas tank  valve and gas is leaking around the fitting. I seem to remember reading a post in the past where someone had this same experience, but never saw a response as to the fix. Appreciate any help on this.

Shanagolden

[Fred Koehlmann]

You don't mention if the tank is metal or one of those plastic/fiberglass tanks. I mention this because we use to have one of those glass tanks because we thought it great that you could see the level within, but it only lasted one season. The metal fitting at the top developed a leak against the glass tank where is had been screwed or glassed into the tank. I speculated that the occasional violent bouncy of the boat over waves, caused the fitting to wrench loose. A tank supplier tried to seal it but was never successful. I'll never go back to that type of tank for on-board use.