316 Stainless Steel Wafer Check Valve — SS316 Disc and Spring, PN 25/40, up to 180 °C

Cematic's 316 stainless steel wafer check valve allows the flow of liquids or gases in only one direction and prevents unwanted backflow in piping systems. Its wafer style, unlike flanged or clamp check valves, is installed directly between existing flanges without additional parts, reducing the space required and facilitating its integration. This reduces the space required and facilitates its integration in installations with space restrictions or many retention points.

The use of 316 stainless steel for the body, disc, and spring also provides excellent corrosion resistance in aggressive environments. Consequently, it is suitable for water, chemicals, hydrocarbons, and gases where carbon steel does not offer sufficient chemical resistance.

Operating Principle — Wafer Check Valve with Spring

The wafer check valve operates automatically without external actuation. When the fluid flows in the correct direction, the pressure overcomes the spring's force, opening the disc and allowing flow. When the flow stops or reverses, the spring returns the disc to its seat, closing the valve immediately. This protects the line against any fluid backflow without operator intervention.

The disc design also allows for a quick response and precise closure, minimizing pressure losses. It also reduces water hammer that can occur with slow closures in high-velocity fluids.

Wafer Style vs. Other Check Valve Types

The selection of the check valve style also depends on the type of installation and available space. The wafer style is suitable in the following cases:

• Installation between existing flanges: The wafer valve is held between two flanges by the studs of the connection, so it does not require its own flanges or special connections. Consequently, it reduces the cost and weight of the assembly compared to check valves with their own flanges.
• Limited space in the line: The compact profile of the wafer style also takes up significantly less length in the line than a long-body check valve. Its low weight also facilitates installation in suspended pipes or in spaces with limited access.
• Large diameters up to 12": In large diameter lines, the wafer style is also the most economical alternative to the long-body check valve. Therefore, it is the standard style in industrial plants.

Construction Materials

The body is made of 316 stainless steel (SS316), which is the standard material for services with aggressive fluids. Its molybdenum content also offers greater resistance to chlorides and acids than SS304. The disc is also made of SS316, maintaining material consistency throughout the fluid contact area. The spring is made of SS316, ensuring stable closing force. It even resists frequent thermal cycles between -20 °C and 180 °C. Finally, all components are made of the same material, eliminating the risk of galvanic corrosion between parts of different metals.

Technical Specifications

Fluid Compatibility

This 316 stainless steel wafer check valve is compatible with a wide range of industrial fluids. The main groups are described below:

• Potable water and process water — SS316 resists corrosion from process water, including water with chlorides; therefore, it is suitable for water distribution and treatment systems
• Corrosive chemical fluids — SS316's resistance to aggressive acids and chemicals makes it suitable for chemical process systems; however, verify specific compatibility with Cematic's technical team for extremely aggressive fluids
• Petrochemical fluids and hydrocarbons — SS316 resists hydrocarbons and petroleum derivatives common in refineries and petrochemical plants; also, the maximum temperature of 180 °C covers most process services in these plants
• Refrigeration and HVAC fluids — in HVAC and refrigeration systems, this valve ensures efficient one-way flow; however, for specific refrigerants, verify compatibility with the technical team
• Steam and high-temperature fluids up to 180 °C — SS316 and the SS316 spring maintain their mechanical properties up to 180 °C; also, the wafer style facilitates maintenance in steam lines where space between flanges is limited

Applications of the Stainless Steel Wafer Check Valve

Chemical Industry

The 316 stainless steel wafer check valve is suitable for systems handling corrosive chemicals. Its corrosion resistance also ensures a long service life with aggressive fluids, reducing maintenance costs compared to valves with lower chemical resistance. Consequently, it reduces maintenance and replacement costs in chemical process installations.

Potable Water and Wastewater Treatment Systems

In water distribution systems and treatment plants, this valve also prevents water backflow and protects the system. SS316 also resists corrosion from chlorides and disinfection agents present in treated water. Therefore, it is a more durable alternative to cast iron or carbon steel check valves in these services.

Petrochemical Industry

In installations with petroleum products, the resistance of SS316 is essential. It also ensures the integrity of the valve in contact with hydrocarbons at high temperatures. Therefore, this wafer check valve protects pumps and downstream equipment from any flow reversal. Its compact design also facilitates installation in large diameter lines where space is limited.

Refrigeration and HVAC Systems

In HVAC and refrigeration systems, this valve ensures one-way flow, protecting compressors and heat exchangers from reverse flow. Its quick response also minimizes water hammer during closure, protecting the mechanical integrity of the pipes and equipment in the system.

Power and Generation Systems

In power plants, this check valve prevents reverse flow that could damage turbines, pumps, and other equipment. Therefore, it is the standard protection component in steam and boiler water lines. Therefore, it is the standard protection component in steam and boiler feedwater lines. Also, the temperature range up to 180 °C and PN 25/40 pressure cover most auxiliary services in generation plants.

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Technical Data Sheet