Valves

Function and operating frequency decide which valve suits a line. Ball valves give quick shut-off, gate valves suit occasional full-bore isolation, and check valves stop reverse flow on pump lines. For pressure valves, note the set pressure range. Give the nominal size, end connection, body material, such as brass, cast iron or stainless steel, and pressure rating. Valves on pressurised lines should be fitted by trained plumbers.