Circle Seal Controls – Fluid Control Products offers a wide range of check valves. Operating pressure ranges include 0–25, 0–800, 0–3000, 0–5000, 0–6000, and 0–10,000 psig. Body materials typically include 303 & 316 stainless steel and brass. Operating temperatures cover −70° to +550° F (−390° to +288° C).