What are the main types of check valves?

The 6 main types of industrial check valves are: (1) Swing Check Valve – hinged disc swings open/closed, best for large sizes, (2) Dual Plate Check Valve – two half-discs in wafer body, compact and lightweight, (3) Disc Check Valve (Non-Slam) – spring-loaded single disc in wafer body, quick closing, (4) Lift Check Valve – globe-type body, disc lifts vertically, for horizontal or vertical flow, (5) Silent/Nozzle Check Valve – spring-assisted axial flow, zero water hammer, (6) Inline High Pressure Check Valve – compact forged body for 3000-10000 PSI.

Which check valve prevents water hammer?

Silent (nozzle type) check valves are specifically designed to prevent water hammer. They use a spring-loaded disc that closes before reverse flow develops, eliminating the pressure surge that causes water hammer. Dual plate check valves also reduce water hammer significantly due to their short disc travel and spring-assisted closure. Disc check valves (non-slam) with spring-assisted closure also minimize water hammer. Swing check valves are the most susceptible to water hammer because they rely on reverse flow to close.

Swing check valve vs dual plate check valve – which is better?

Dual plate check valves are better when: space is limited (wafer body = shorter face-to-face), weight matters (40-80% lighter), water hammer prevention is important, or vertical installation is needed. Swing check valves are better when: maximum flow capacity is needed (larger port), low pressure drop is critical, the valve needs to handle dirty or viscous fluids, or lower cost is important for large sizes. Both are suitable for Class 150 to 600 service.

Can check valves be installed vertically?

It depends on the type. Swing check valves: horizontal only (gravity-assisted closure). Dual plate check valves: horizontal or vertical (spring-assisted). Disc check valves: horizontal or vertical (spring-assisted). Lift check valves: horizontal for standard, vertical for piston type. Silent/nozzle check valves: horizontal or vertical (spring-assisted). Always verify with the manufacturer for specific models.

Types of Check Valves Compared: Swing, Dual Plate, Lift, Silent & Nozzle

February 11, 2026 12 min read Valve Comparison

Check valves (also called non-return valves or NRVs) allow fluid to flow in one direction and automatically prevent backflow. But with 6 major types available — each with distinct advantages — choosing the right check valve for your application is critical. This guide compares all types head-to-head using real catalogue data, covering working principles, materials, dimensions, and selection criteria.

1. Swing Check Valve

Swing Check Valve – BS 1868 / ANSI B16.34 / API 6D

How it works: A disc hinged at the top swings open when forward flow pushes it. When flow stops or reverses, gravity and reverse pressure swing the disc back onto the seat.

Design standards: BS 1868, ANSI B16.34, API 6D

Pressure classes: 150# to 2500#

Sizes: 1" to 24" (DN25 to DN600)

End connections: Flanged (ASME B16.5), Butt-weld (ASME B16.25)

Key materials: Body: WCB / CF8 / CF8M. Disc: AISI 410. Hinge pin: AISI 410. Seat: AISI 410 or 13% Cr. facing.

Advantages: Full bore — lowest pressure drop of all check valves. Handles dirty/viscous fluids. Available in all pressure classes up to 2500#.
Limitations: Horizontal installation only. Susceptible to water hammer (disc slams on reverse flow). Large face-to-face dimension. Heavy.

2. Dual Plate Check Valve (Wafer Type)

Dual Plate Check Valve – API 594 / API 6D

How it works: Two semicircular plates (half-discs) are mounted on a central hinge pin with torsion springs. Forward flow pushes the plates open. Springs assist closure when flow stops.

Design standards: API 594, API 6D

Pressure classes: 150# (wafer to suit ASME B16.5, PN10, PN16, D-Table)

Sizes: 2" to 24" (DN50 to DN600)

End connections: Wafer type (sandwiched between flanges)

Key materials: Body: WCB. Closure plates: ASTM A217 CA-15. Springs: Inconel X-750. Seals: PTFE. Hinge pin: AISI 410.

Test pressures (Class 150): Body 30 kg/cm², Seat 22 kg/cm².

Advantages: Compact wafer body — 40–80% lighter than swing check. Short disc travel = faster closure = reduced water hammer. Works horizontal or vertical. Low cost.
Limitations: Not full bore (slight restriction). Not suitable for viscous or dirty fluids (small clearances). Limited to Class 150–300 in standard configuration.

3. Disc Check Valve (Non-Slam)

Disc Check Valve – API 594 / API 6D

How it works: A single circular disc with a central guide stem is held closed by a spring. Forward flow pressure overcomes the spring and lifts the disc. When flow stops, the spring snaps the disc closed before reverse flow develops.

Design standards: API 594, API 6D

Pressure classes: PN-40 (also available for 150#)

Sizes: ½" to 8" (DN15 to DN200)

End connections: Wafer (sandwiched between flanges)

Key materials: Body: Investment cast CF8/CF8M (SS 304/316). Disc: SS 304/316 investment cast. Spring: SS 304/316.

Test pressures (PN-40): Body 60 kg/cm², Seat 44 kg/cm².

Advantages: Quick closing — prevents water hammer. Silent operation. Low pressure drop. Compact and lightweight. Works horizontal or vertical. Investment cast for precision.
Limitations: Small sizes only (up to 8"). Spring creates some cracking pressure. Not suitable for viscous fluids.

4. Lift Check Valve (Globe Type)

Lift Check Valve – BS 1873 / API 623 / API 602

How it works: Uses a globe-type body. The disc lifts vertically off the seat when forward flow creates sufficient pressure differential. Disc drops back by gravity (or spring) when flow stops.

Design standards: BS 1873, API 623, API 602

Pressure classes: 150# to 300# (flanged), PN-40 (DIN)

Sizes: 1" to 12" (DN25 to DN300)

End connections: Flanged (ASME B16.5), Butt-weld (ASME B16.25), DIN flanges

Key materials: Body: WCB. Disc: AISI 410. Seat ring: AISI 410. Cover: WCB. Studs: A193 B7 / A194 2H. Gasket: spiral wound metallic.

Advantages: Globe-type body allows good flow regulation. Metal-to-metal or soft-seated sealing. Optional spring loading for quick closure. Robust for high pressure and temperature.
Limitations: Higher pressure drop than swing check (tortuous flow path). Horizontal installation for standard type. Heavier than wafer-type valves.

5. Silent Check Valve (Nozzle Type)

Silent / Nozzle Check Valve

How it works: A spring-loaded disc moves axially (inline) within a nozzle-shaped body. The spring begins closing the disc as soon as forward flow decelerates — completing closure before any reverse flow develops. Zero slam, zero water hammer.

Sizes: 1½" to 12"

End connections: Flanged (ASME B16.5)

Key materials: Body: WCB / CF8 / CF8M. Disc: AISI 410 / SS 304/316. Spring: Inconel X-750.

Advantages: Eliminates water hammer completely. Silent operation. Works in any orientation. Precision-lapped nozzle face. Fast response to flow changes.
Limitations: Higher cost than swing or dual plate. Spring creates cracking pressure. Not suitable for dirty/viscous fluids.

6. Inline High Pressure Check Valve

Inline HP Check Valve – BS 5155 / BS 6755

How it works: A compact forged body with spring-loaded poppet disc. Positive closure at up to 10,000 PSI. Hex body for wrench installation. Screwed or socket weld connections.

Pressure ratings: 3,000 / 6,000 / 10,000 PSI

End connections: Screwed (BSP/NPT), Socket Weld

Key materials: Body: A105 / A182 F316. Poppet: AISI 410 / SS 316. Spring: SS.

Advantages: Ultra-compact. Ultra-high pressure. Forged body for strength. Easy wrench installation. Metal or soft seat.
Limitations: Small sizes only. Screwed/SW connections only. Not for large flow volumes.

Master Comparison Table

Feature	Swing	Dual Plate	Disc (Non-Slam)	Lift	Silent/Nozzle	Inline HP
Water Hammer	High risk	Low	Very low	Medium	Zero	Low
Pressure Drop	Lowest	Low	Low	Higher	Low	Low
Weight	Heavy	Light	Light	Heavy	Medium	Light
Size Range	1"–24"	2"–24"	½"–8"	1"–12"	1½"–12"	¼"–2"
Max Class	2500#	150–300#	PN-40	300#/PN40	150#	10000 PSI
Installation	Horizontal only	H or V	H or V	Horizontal	H or V	Any
Dirty Fluids	Good	Poor	Poor	Fair	Poor	Fair
Closing Speed	Slow	Fast	Very fast	Medium	Very fast	Fast
Cost	Medium	Low	Low	Medium	Higher	Low
Body Type	Flanged	Wafer	Wafer	Flanged	Flanged	Forged

Quick Selection Guide

General service, large sizes, low ΔP needed → Swing Check Valve
Space/weight limited, moderate water hammer concern → Dual Plate Check Valve
Small sizes, clean fluids, non-slam needed → Disc Check Valve
High pressure/temperature, globe body needed → Lift Check Valve
Zero water hammer required, pump discharge → Silent/Nozzle Check Valve
Ultra-high pressure (3000–10000 PSI) → Inline HP Check Valve

Conclusion

No single check valve type is best for every application. The right choice depends on your specific requirements: pressure class, size, installation orientation, water hammer tolerance, fluid cleanliness, and budget. Use the comparison table and selection guide above as your starting point, and consult with our engineering team for complex applications requiring specialized solutions.

Need Check Valves? We Have All Types

Swing, dual plate, disc, lift, silent, and inline HP check valves. All sizes and materials. EN 10204 3.1 MTCs.

Swing Check Dual Plate Silent / Nozzle Lift Check Inline HP