| Swing Check Valve | A hinged disc swings open with forward flow and closes by gravity or reverse flow. | DN50–DN1200 (2–48 in) | PN10–PN100 Class 150–600 | Carbon steel, stainless steel, ductile iron, alloy steel | Approximately −29°C to 425°C (−20°F to 797°F) | Water pipelines, oil transfer, refining, power plants, general process piping | API 6D, API 594, ASME B16.34, EN 12334, EN 1092-1 |
| Wafer Check Valve | A compact disc or split-disc assembly is held between pipe flanges and closes rapidly. | DN50–DN600 (2–24 in) | PN10–PN40 Class 150–300 | Ductile iron, carbon steel, stainless steel, duplex stainless steel | Approximately −29°C to 260°C (−20°F to 500°F) | HVAC, water treatment, chemical processing, fire protection and utility systems | API 594, API 6D, EN 12334, ASME B16.34 |
| Dual-Plate Check Valve | Two spring-loaded plates close independently to reduce reverse-flow shock and water hammer. | DN50–DN1200 (2–48 in) | PN10–PN420 Class 150–2500 | Carbon steel, stainless steel, duplex stainless steel, nickel alloys | Approximately −46°C to 500°C (−51°F to 932°F) | High-pressure oil and gas, steam, power generation, compressor discharge lines | API 594, API 6D, ASME B16.34, ISO 14313 |
| Lift Check Valve | A guided piston or disc lifts from its seat under forward pressure and returns when flow reverses. | DN15–DN300 (½–12 in) | PN16–PN420 Class 150–2500 | Forged carbon steel, stainless steel, alloy steel | Approximately −29°C to 560°C (−20°F to 1040°F) | Steam, boiler feedwater, high-temperature process and refinery piping | API 602, ASME B16.34, BS 1868, EN 12516 |
| Piston Check Valve | A piston moves vertically inside a cylinder, often using a dashpot effect for controlled closing. | DN15–DN300 (½–12 in) | PN16–PN420 Class 150–2500 | Carbon steel, stainless steel, chrome-moly alloy steel | Approximately −29°C to 550°C (−20°F to 1022°F) | Steam lines, boiler systems, petroleum refining and high-pressure process services | API 602, ASME B16.34, BS 1868 |
| Ball Check Valve | A ball moves away from the seat during forward flow and seals the passage during reverse flow. | DN15–DN300 (½–12 in) | PN10–PN100 Class 150–600 | Cast iron, ductile iron, carbon steel, stainless steel, lined alloys | Approximately −20°C to 200°C (−4°F to 392°F) | Wastewater, slurry, sewage, chemical dosing and low-maintenance pumping systems | EN 12334, DIN standards, ASME B16.34, EN 1092-1 |
| Non-Slam Check Valve | A spring-assisted or axial-flow design closes before significant reverse flow develops, minimizing hydraulic shock. | DN25–DN1200 (1–48 in) | PN10–PN420 Class 150–2500 | Carbon steel, stainless steel, duplex stainless steel, nickel alloys | Approximately −46°C to 500°C (−51°F to 932°F) | Long pipelines, pump discharge, water transmission, LNG and critical process systems | API 6D, API 594, ISO 14313, ASME B16.34 |