Brass foot valves prevent water from back flowing into the water source. Boshart Industries Foot Valve, Lead-Free, Series: 17YBFVNL, 1 in Nominal, FNPT End Style, 200 psi Pressure, 180 deg F, 4.61 in Inlet to Outlet Length, Brass Body, Stainless Steel Trim, NBR Softgoods, 4.65 in L x 1.7 in W x 1.85 in H Dimensions