Valterra Double Union Spring Non Return Valve, this Valterra Double Union Spring Non Valve offers minimal resistance and the benefit of waste particles that may be eliminated by unscrewing the double union fittings. The Double Union Spring Non Return Valve is a simple way to avoid backflow in pipework where it is unwanted, such as in pumped systems or where Elecro heaters are installed in line. This Double Union Spring Non Return Valve (swing check) Valve is most likely unique in its design, and it is the first we have found where the valve can be inspected for periodic cleaning, etc. The non-return valves with springs provide little back pressure on the pumps, and the swing check simply swings out of the way. It will fit any 1.5 inch or 2 inch imperial pressure pipe and is solvent weldable as well. To utilise these flapper valves with standard Black Solvent Waste Pipe, reducer sleeves can be pasted into the socket unions.
