Check Valve Types Explained: A Guide to 20 Structural Designs and Their Standards
Selecting the right check valve is crucial for preventing backflow and ensuring system integrity. With numerous designs available, each tailored for specific pressure, flow, and installation conditions, making the correct choice can be complex. This guide provides a clear overview of 20 common check valve structures, grouped by their operating principle, along with key design standards to inform your selection process.The main check valve product names of China Check Valve Network include:Welding Power Station Lift Check Valve，ANSI Flange Power Station Swing Check Valve，Flange Swing Low Temperature Check Valve，DIN Lift Check Valve，Multifunctional Silent Lift Check Valve，Flange Lift Ammonia Check Valve，
1. Lift Check Valves
This family operates via a disc or piston that moves vertically on the seat. Installation orientation is critical for proper function.Check Valve Standard
Vertical/Straight-Through Lift Check Valves: Feature horizontal, angled, vertical, or Y-pattern flow paths. Body-bonnet connections are typically flanged or threaded. Disc designs vary, including ball, flat-seat plug, and cone-seat plug types. Common governing standards include BS 5352, JB/T 7746, and GB/T 12235.
Internal Pressure Seal (IPS) Lift Check Valves: Utilize the system pressure to seal the bonnet joint, making them suitable for high-pressure services. Ends can be flanged, butt-weld, or socket-weld. The primary design standard is ASME B16.34.Check Valve manufactor
Spring-Assisted Lift Check Valves: Often designed with an angled flow path, an internal spring ensures positive and rapid closure, ideal for pulsating flow or where fast response is needed. Standards include BS 1868 and ASME B16.34.
Y-Pattern Lift Check Valve with Bypass Tube: A straight-through design featuring a bypass tube between the disc and outlet for smoother flow guidance. It uses a pressure-seal bonnet and conforms to standards like ASME B16.24.
2. Swing Check Valves
In these valves, a disc swings on a hinge or trunnion pin. They generally offer lower flow resistance and more flexible installation options than lift checks.
Standard Swing Check Valve: The most common type, with a straight-through cast steel body. The seating surfaces are often hard-faced. It conforms to standards such as GB/T 12236 and API 6D.
Dual Plate Wafer Check Valve: A compact, lightweight design where two spring-loaded half-discs pivot on a central pin. Its space-saving design makes it popular for API and general industrial piping, governed by JB/T 8937 and API 6D.
Non-Slam / Controlled Closing Swing Check Valves: Incorporate external hydraulic dampers, internal pistons, or lever-and-weight mechanisms to slow the disc's closing, preventing water hammer. Relevant standards include JIS B2074, API 594, and API 6D.
Internal Pressure Seal (IPS) Swing Check Valve: Similar to the IPS lift check, this design uses system pressure to seal the bonnet for high-pressure applications, per ASME B16.34.
3. Special Purpose & Other Check Valve Designs
These valves are engineered for specific applications or unique performance requirements.
Butterfly Check Valve: Operates like a butterfly valve, where a disc rotates on a central shaft. It is simple and offers quick response.
Ball Check Valve: Uses a rubber-coated or solid ball as the closing element, providing good sealability with minimal wear. Available in single-ball (small bore) and multi-ball (larger bore) configurations.
Damped Butterfly Check Valve: Features a damper cylinder and pin on the disc to control the closing speed for silent operation, typically adhering to API 6D.
Foot Valve (Bottom Valve): A specialized check valve installed at the pump suction inlet to retain prime. Designs include single-disc lift and dual-disc swing types, referencing standards like BS 5352 and API 594.
Stop Check Valve: Functions as both an isolation (stop) valve and a check valve, critical in systems like boiler feedwater lines. It is designed per standards such as BS 1873.
Vacuum Breaker & Pressure/Vacuum Relief Valve: Used in specific scenarios to prevent tank collapse or overpressure by controlling the differential pressure between a system and the atmosphere.
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