Check Valve Types: Swing Check, Lift Check, Dual Plate, and More — Complete Guide
Quick Answer: Check valves prevent backflow in piping systems. The main types are swing check valves, lift check valves, dual plate (wafer) check valves, and tilting disc check valves. Each type has distinct flow characteristics, pressure ratings, and installation requirements that make them suitable for specific applications.
Check Valve Comparison Table
| Type | Flow Resistance | Pressure Rating | Size Range | Best Application |
|---|---|---|---|---|
| Swing Check | Low | Class 150-2500 | 2″ – 48″ | Horizontal pipelines, low velocity |
| Lift Check | High | Class 150-2500 | 1/2″ – 12″ | Vertical lines, clean fluids |
| Dual Plate | Very Low | Class 150-2500 | 2″ – 36″ | Compact spaces, water/hydrocarbon |
| Tilting Disc | Very Low | Class 150-900 | 4″ – 36″ | Low pressure drop, large diameter |
1. Swing Check Valve
The swing check valve uses a hinged disc that swings open with forward flow and closes when flow reverses. Its key features include:
- Low pressure drop: The disc swings fully out of the flow path
- Simple construction: Few moving parts, reliable and easy to maintain
- Large size capability: Available up to 48″ or larger
Swing check valves are suitable for horizontal or vertical upward flow. They are commonly used in water supply, sewage, and general industrial applications. Available in bolted cover or pressure seal designs. See our swing check valve products.
2. Lift Check Valve
Lift check valves operate with a disc that lifts vertically off the seat as flow passes through. They are best suited for:
- Steam and condensate systems
- High-pressure services
- Clean, non-viscous fluids
- Vertical piping where gravity helps closing
Lift checks closely resemble globe valves in design and have higher pressure drop compared to swing checks. They are available in threaded, flanged, and socket weld ends.
3. Dual Plate (Wafer) Check Valve
Dual plate check valves use two spring-loaded plates that fold open with flow and close when flow stops. Benefits include:
- Compact design: Short face-to-face dimension fits between flanges
- Light weight: Up to 80% lighter than swing check valves
- Quick closing: Spring-assisted closure minimizes water hammer
- Low cost: Economical for large diameter applications
These are the most popular check valve type for water, HVAC, and general industrial services. Browse our dual plate check valves.
4. Tilting Disc Check Valve
Also known as extraction check valves or slow-closing check valves, these are designed to prevent slam and water hammer. They are essential in power plant extraction steam lines where sudden reverse flow can cause catastrophic damage. See our power station check valves for turbine extraction applications.
Check Valve Selection Guide
When selecting a check valve, consider these factors in order:
- Fluid type — Clean liquid, gas, steam, or slurry?
- Flow velocity — Minimum velocity must lift the disc fully open
- Pressure rating — Match or exceed system design pressure
- Pipe orientation — Horizontal, vertical up, or vertical down?
- Space constraints — Can you accommodate a swing check or need a compact wafer?
- Water hammer risk — Quick-closing or slow-closing design required?
Frequently Asked Questions
Q: Can check valves be installed horizontally?
A: Most check valves can be installed horizontally. Swing checks and dual plates work horizontally or vertically upward. Lift checks should be installed vertically for best performance.
Q: What causes check valve water hammer?
A: Water hammer occurs when reverse flow velocity is high before the disc closes. Using spring-assisted or slow-closing check valves can prevent this.
Q: How often should check valves be inspected?
A: Annual inspection is recommended. Look for seat wear, hinge pin corrosion, and disc damage. In critical services, inspect every 6 months.
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Need expert advice on check valve selection? Contact Vornet Valve for technical support and quotes.