Smith-Cooper International 9191 Series Brass Swing Check Valve, 4" NPT Female, Non-Potable Water Use Only Made from brass for higher corrosion resistance than steel Female NPT threads for connecting to male threaded pipes Maximum pressure ratings of 200 psig for WOG and 125 psig for SWP Maximum working temperature of 350 degrees Fahrenheit Meets NSF/ANSI 61-8 for quality assurance Product contains brass which does not meet federal and state requirements for drinking water.