Check valves automatically prevent reverse flow in piping systems, protecting pumps, compressors, and process equipment from backflow damage. AQ Process Systems sources and exports the full range of check valve types for steam, process, water, and pipeline applications.
We offer swing check, piston (lift) check, dual plate (wafer) check, tilting disc, and non-slam (dashpot-equipped) check valves in sizes from 1/2" to 48". Materials include carbon steel, stainless steel, chrome-moly, duplex, and exotic alloys.
Selecting the correct check valve type is critical for preventing water hammer and ensuring reliable operation. We can advise on the best type for your application based on flow velocity, piping configuration, and acceptable slam pressure.
| Product | Specification | Description |
|---|---|---|
| Swing Check Valves | ||
| Swing Check Valves | 2", 48" | Class 150-2500 | Flanged or BW | Full-bore swing check valves, low pressure drop, suitable for horizontal and vertical (upflow) installations. Bolted cover for access. |
| Tilting Disc Check Valves | 2", 48" | Class 150-2500 | Reduced slam | Tilting disc check valves with the disc pivot above centre, faster closing with reduced slam compared to standard swing checks. |
| Lift / Piston Check Valves | ||
| Piston Check Valves | 1/2", 24" | Class 150-2500 | Flanged, SW, threaded | Piston (lift) check valves with guided piston disc, positive sealing, suitable for pulsating flow and compressor discharge. |
| Ball Check Valves | 1/2", 2" | Class 800 | Threaded or SW | Small-bore ball check valves using a free-floating ball as the closure element, simple, reliable backflow prevention. |
| Wafer & Non-Slam | ||
| Dual Plate (Wafer) Check Valves | 2", 48" | Class 150-2500 | Wafer or lug | Compact dual plate (butterfly-style) check valves, short face-to-face, light weight, spring-assisted closing to reduce slam. |
| Non-Slam Check Valves | 2", 48" | Class 150-600 | Dashpot equipped | Non-slam check valves with external dashpot controlling closure speed, for applications where water hammer must be eliminated. |
| Nozzle Check Valves | 1", 24" | Class 150-2500 | Axial flow | Axial-flow nozzle check valves with spring-loaded disc, extremely fast closing, very low pressure drop. Ideal for compressor discharge. |
We supply swing check, tilting disc, piston (lift) check, ball check, dual plate (wafer) check, non-slam (dashpot) check, and nozzle check valves. Each type has specific advantages, swing checks for low pressure drop, dual plates for compact installation, nozzle checks for fast closing, and non-slam for water hammer prevention.
Water hammer from check valve slam is prevented by selecting a fast-closing check valve type (dual plate, tilting disc, or nozzle check), adding a dashpot or spring to control closing speed, or ensuring the valve is correctly sized for the flow velocity. We can advise on the best solution for your specific installation.
A dual plate (also called butterfly check or wafer check) valve uses two spring-loaded semi-circular plates that fold open with forward flow and snap shut on flow reversal. They are very compact (wafer body fits between flanges), lightweight, and close quickly, reducing slam. Popular for pump discharge, compressor lines, and space-constrained installations.
Yes. Piston (lift) check valves, spring-loaded dual plate checks, and spring-loaded nozzle checks all work in vertical pipes (upward flow). Standard swing check valves only work reliably in horizontal pipes or vertical pipes with upward flow. We advise on the correct type for your pipe orientation.
Yes. For pump discharge lines where water hammer must be prevented, we supply non-slam check valves with external dashpots (hydraulic or pneumatic) that control the closing speed. We also offer spring-loaded dual plate and nozzle checks that close before flow reversal occurs, eliminating slam entirely.
Share your valve specification, size, pressure class, material, end connections, we respond within 24 hours.