An automatic recirculation valve (PSG-N) that protects centrifugal pumps from thermal and hydraulic overload at low load. It automatically controls the bypass flow to match the minimum flow the pump needs. Thanks to the inline design, all internals can be removed without taking the valve out of the pipeline.
| Series | PSG-N (Type 75, 76, 77) |
| Size | DN 32 (NPS 1.5) to DN 200 (NPS 8) |
| Pressure Rating | PN 10 to PN 250 (CL 150 to CL 1500) |
| Body Material | Cast steel GP240GH+N (ASTM A 216 WCB) |
| Pressure Letdown | Low-noise single- or multi-stage |
| End Connection | Flanged |
| Bypass Service | Type 75/75-K/75-T: bypass pressure drop up to 20 bar (up to 25 bar with nonreturn valve or orifice plate in bypass flange), bypass closes at about 35 % of max. process flow; Type 76/77: pressure drops between 10 and 200 bar, bypass closes at about 50 % of max. process flow; main check valve leakage <= 0.01 % of max. kv (EN 1349 IV L1) for 75/75-T |
| Seat Material | Type 75/75-K/75-T: PN 16~40: 1.4021 / Type 76/77: 1.4021 (Type 420) |