PR-500 Percision Plumbing Products Prime-Rite Trap Primer ValveThe Prime Rite automatic pressure drop activated trap primer valve will prime up to 2 floor drains with our patented distribution DU-U and DU-4 units. System operating range is 20 psi minimum to 80 psi (138 to 552 kpa) maximum. The valve requires a 10 psi (70 kpa) pressure drop across the valve to activate and will deliver a metered amount of water to the floor drain. Trap primer is to be connected to a cold water supply only. Constructed of 360 brass, EPDM E70 O-rings, Dow #7 Silicone, #60 stainless steel mesh screen.No Adjustment RequiredAutomatically Maintains a Constant Water Seal in Floor Drain TrapsThis Priming Valve Contains: No Springs, Diaphgrams, or plastic parts and uses #60 Mesh Stainless Steel Screen