Series 601, 601S Bronze Maxi-Flo Check Valves are used to prevent the effects of water hammer in the piping system. They feature a bronze body, Viton disc and integral brass seat. Series 601, 601S silent check valves have a low pressure drop and can be installed in a horizontal or vertical position. Model 601 is available in sizes 1/4 to 1/2 in. (8 to 15mm) with threaded connections. Model 601S is available in sizes 1/2 to 1 in. (15 to 25mm) with solder connections. Maximum Pressure: 400psi (27.6 bar) WOG (non-shock) @ 100°F (38°C).