Check Valves

Check valves prevent reverse flow in piping systems — they open with forward flow velocity and close when forward flow stops or reverses, protecting pumps, compressors, and process equipment from backflow damage. No external actuation required; the flow itself drives opening and closing through disc weight, spring force, or fluid dynamics. FLOWKS manufactures eight check valve configurations spanning four closing mechanisms and three body formats. Swing check valves use a full disc swinging on a hinge pin — 80° opening angle gives near-full-bore passage and minimal pressure drop, gravity closure, the default for steady-flow pump discharge at 2"-24". Butt weld swing check valves apply forged bodies and butt weld connections at Class 150-2500 where flanged gaskets become reliability liabilities under high-pressure impact slamming. External pin swing check valves add a hydraulic dashpot to the hinge pin — controlled closing over 1-3 seconds eliminates water hammer on pump-trip and long-pipeline applications. Lug type dual plate check valves split the closing motion between two half-discs with torsion spring assist — shorter travel means faster closure (0.2-0.5 seconds), lug format allows dead-end service, compact face-to-face dimension. Vertical lift check valves lift a disc vertically off the seat with upward flow — short travel distance for fast closure at 1/2"-4", disc guide ensures centered seating, vertical-only installation. Double flanged dual plate check valves provide full flanged structural integrity at 2"-48" and Class 600 where wafer/lug bodies lack sufficient pipeline load resistance. Axial flow check valves move the disc along the flow axis into an upstream cage — full-bore open passage with zero obstruction, lowest pressure drop of any check design, spring-loaded closing for zero-backpressure reliability, specified for compressor discharge and continuous-flow pipeline stations. Wafer single disc swing check valves deliver economy swing check protection at Class 150-300 in thin wafer format — simplest, cheapest, basic reverse-flow prevention for water, HVAC, and general process lines.

FLOWKS check valves provide automatic reverse-flow prevention across the full range of industrial piping sizes and pressures. Swing check valves deliver near-full-bore passage with 80° disc opening and gravity closure — the default for steady-flow pump discharge at 2"-24" Class 150-600. Butt weld swing check valves with forged bodies eliminate flanged connections at Class 150-2500 where gaskets leak under high-pressure disc impact slamming. External pin swing check valves add hydraulic dashpot control for 1-3 second gradual closure that eliminates water hammer on pump-trip and long-pipeline applications. Lug type dual plate check valves close faster with two spring-assisted half-discs — 0.2-0.5 second closure, dead-end service capability, compact face-to-face dimension at 2"-48". Vertical lift check valves provide fast guided closure on small-bore vertical lines at 1/2"-4" where disc alignment precision matters. Double flanged dual plate check valves deliver maximum structural integrity at 2"-48" Class 600 for waterworks and critical pipeline stations. Axial flow check valves offer the lowest pressure drop with full-bore unobstructed passage and spring-loaded closing — compressor discharge and continuous-flow pipeline protection. Wafer single disc swing check valves give economy reverse-flow prevention at Class 150-300 in compact wafer format for water and HVAC service.