4" Cast Iron Check Valve & Strainer – NBR Seat – 5mm Mesh. VS 9780This 4" Cast Iron Check Valve & Strainer is equipped with a NBR Seat and 5mm Mesh, providing reliable fluid flow control and protection from debris. The superior construction ensures long lasting performance in water, steam, and oil applications. Screwed BSPP Cast Iron Body Brass Trim NBR Seat 5mm Mesh Rated PN16, Temperature 10C to 100C.