All Simmons ductile iron check valves are CERTIFIED LEAD FREE, featuring an ASTM A536 ductile iron body with non-toxic polyester powder coated finish. Each valve is furnished with Buna-N O-Ring, stainless steel spring, stainless steel washer, and stainless steel locknut. All valves ¾” through 1 ½” have a working pressure of 400 PSI, while valves 2” and larger have a working pressure of 600 PSI. Check valves rated for 190°F maximum temperature.