Series LF601, LF601S Lead Free* cast copper silicon alloy Maxi-Flo Check Valves are used to prevent the effects of water hammer in the piping system. They feature a Lead Free* copper silicon alloy body, Viton disc and integral copper silicon alloy seat. Series LF601, LF601S silent check valves have a low pressure drop and can be installed in a horizontal or vertical position. Model LF601 is available in sizes 1/4 to 1/2 in. (8 to 15mm) with threaded connections. Model LF601S 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).