Plumbing Valves

About plumbing valves

Plumbing valves are mechanical devices that control the flow of fluids through a piping system by opening, closing, or partially obstructing passageways. Key types include ball valves, which use a pivoting ball with a bore to control flow; gate valves, which employ a wedge-shaped gate that moves perpendicular to the flow; globe valves, characterized by their spherical body and a movable disc that regulates flow via throttling; butterfly valves, utilizing a rotating disc to control flow; and check valves, designed to permit fluid flow in only one direction. Selection criteria typically involve nominal pipe size (NPS) or DN, pressure ratings (e.g., ANSI Class 150, 300, or PN10, PN16), and connection types such as NPT, BSPP, BSPT, flanged (e.g., ASME B16.5), or welded ends. Actuation methods range from manual levers or handwheels to pneumatic, hydraulic, or electric actuators. Common materials include brass, bronze, cast iron, ductile iron, carbon steel (e.g., A216 WCB), stainless steel (e.g., 304, 316), and various plastics like PVC or CPVC, chosen based on fluid compatibility, temperature, and pressure requirements. Internal trim materials, such as seat and seal compounds (e.g., PTFE, EPDM, Viton), are critical for sealing performance and longevity.