The DPX gas supply from the DPX surface unit box is reduced down to intermediate pressure, 14 bar in the PX+ regulator. The regulator is a pressure balanced piston regulator of the counter flow model whose function is described in section Regulator for buoyancy and bail-out breathing on page 48.

The regulator is fitted with a relief valve that opens at circa 20 bar, a under water quick coupling and a PX+ quick coupling hose with the same construction as described in section Gas hoses on page 51. The high pressure outlet is plugged.