Jim ....Hasnt your regulator got a spare threaded port to screw the relief valve into?

Some regulators have 4 threaded ports ...H.P. Inlet from bottle .... L.P. outlet...plus 2 extra ports for gauges H.P. and L.P.

Simply screw your relief valve into the port that connects internally to your H.P. inlet.

B.T.W. Extinguisher threads are ODD.

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