316 Stainless Steel Swing Wafer Check Valve — Viton O-ring, PN 25/40

Cematic's 316 stainless steel swing wafer check valve allows flow in only one direction and prevents fluid backflow using a swing-type disc. Unlike spring-loaded check valves, the swing disc does not rely on a spring to close.

This makes it more suitable for large diameters and fluids with particles where a spring could become clogged. Additionally, its construction from SS316 CF8M with a Viton O-ring provides high corrosion resistance. It also ensures chemical compatibility with aggressive fluids up to 180 °C.

Its wafer-type design is also compact and installs directly between two existing flanges without the need for additional parts. Consequently, it facilitates integration into piping systems with space restrictions and simplifies installation compared to long-body check valves.

Operating Principle — Swing Type Disc

The disc of the swing wafer check valve oscillates on a horizontal pivot mounted on the upper part of the body. When fluid flows in the correct direction, pressure pushes the disc upwards, thus opening it and allowing passage.

When the flow stops or reverses, however, the disc falls by gravity and automatically seals the seat. This ensures reliable closure without the need for a spring.

The absence of a spring is also the differentiating advantage of this type of check valve. Therefore, it is particularly suitable for large diameter lines where conventional springs lose effectiveness. It is also suitable for fluids with particles that could clog or degrade a conventional spring.

Swing vs. Spring-Loaded Disc — when to choose each type

The selection between a swing disc and a spring-loaded disc also defines the behavior of the check valve under different operating conditions:

• Swing disc (this product): Closes by gravity, no spring. Therefore, it is suitable for large diameters, fluids with particles, viscous fluids, and applications where the spring could fail or degrade due to the fluid. However, it requires horizontal installation for gravity to operate correctly on the disc.
• Spring-loaded disc: Its closure is faster and it can be installed in any position — horizontal or vertical. It also performs better in clean, low-viscosity fluids at high speed. See 316L SS spring-loaded wafer check valve →

Construction Materials

The body is made of 316 stainless steel (CF8M), which is the standard material for services with corrosive fluids, as its molybdenum content offers greater resistance to chlorides and acids than SS304. The swing disc is also made of SS316 CF8M, maintaining material consistency in the fluid contact area.

The seal is a Viton O-ring, which is compatible with hydrocarbons, organic solvents, and acids. NBR or EPDM, however, would degrade under these conditions. Finally, the wafer format eliminates the need for its own flanges, reducing overall weight and cost.

Technical Specifications

Fluid Compatibility

This 316 stainless steel swing wafer check valve with Viton O-ring is compatible with the most demanding fluids in the chemical, petrochemical, and industrial sectors. The main groups are described below:

• Corrosive chemical fluids — Viton resists acids, organic solvents, and aggressive chemicals that would degrade NBR; therefore, it is the standard seal in check valves for chemical processes
• Petrochemical fluids and hydrocarbons — Viton resists chemical attack from hydrocarbons and petroleum derivatives; likewise, SS316 CF8M withstands typical temperatures and pressures in refineries and petrochemical plants
• Refrigeration and HVAC fluids — Viton is compatible with most common industrial refrigerants; it also prevents reverse flow that can damage compressors and pumps in HVAC systems
• Potable water and process water — SS316 resists corrosion from chlorides and disinfection agents; however, for water with high concentrations of suspended solids, the swing disc is more suitable than the spring-loaded check valve
• High-temperature fluids up to 180 °C — Viton maintains its sealing properties up to 180 °C; however, verify specific chemical compatibility with Cematic's technical team for extremely aggressive fluids

Applications of the Swing Wafer Check Valve

Chemical Industry

The 316 stainless steel swing wafer check valve is suitable for systems handling aggressive chemicals. The Viton O-ring also resists a wide range of acids, bases, and solvents that would degrade conventional elastomers. Consequently, it ensures a tight seal and long service life in continuous contact with corrosive fluids.

Petrochemical Industry

In installations with petroleum derivatives, Viton also resists chemical attack from hydrocarbons, and SS316 CF8M withstands process conditions. Therefore, this valve operates efficiently in refineries and petrochemical plants, protecting downstream equipment from any flow reversal.

Additionally, the wafer format facilitates installation in large diameter lines where space is limited.

Refrigeration and HVAC Systems

In HVAC and refrigeration systems, this valve also allows efficient unidirectional flow. Viton is also compatible with most common industrial refrigerants. Therefore, it prevents reverse flow that could damage compressors, pumps, and expansion valves in the system.

Power and Generation Systems

In power plants, this check valve also protects critical equipment — turbines, pumps, and boilers — from fluid backflow during shutdowns or system failures. Likewise, the range up to 180 °C and PN 25/40 covers most auxiliary services in power generation plants where protection against reverse flow is required.

Potable Water and Wastewater Treatment

In water distribution systems and treatment plants, this valve also prevents backflow, thus protecting the integrity of the treated supply. The swing disc is also more suitable than the spring-loaded disc in lines with suspended solids. Consequently, its service life is longer in services with low-quality process water or fine particles.

For the complete range of check valves, see check valves collection →

Technical Data Sheet