316 Stainless Steel Swing Wafer Check Valve — Metal Seat, PN16, ANSI Class 150LB

Cematic's 316 stainless steel swing wafer check valve with metal seat ensures unidirectional flow in industrial systems where elastomers are not a viable option. Unlike check valves with Viton or EPDM seats, the CF8M metal seat does not experience chemical or thermal degradation.

Therefore, it is the correct choice for highly corrosive fluids, extreme temperatures, or media with abrasive particles. Its compact wafer design also installs directly between ANSI Class 150LB flanges without the need for additional parts.

All fluid-contacting components—body, disc, and seat—are made of CF8M, maintaining material consistency throughout the process area. Consequently, this eliminates the risk of galvanic corrosion between components of different materials and simplifies plant material specification.

Principle of Operation — Swing Disc with Metal Seat

The disc pivots on a horizontal shaft mounted in the upper part of the body. When fluid flows in the correct direction, pressure pushes the disc upward, opening the passage. When the flow stops, the SS304 spring returns the disc to the metal seat and closes the valve. This way, the closure is automatic without the need for operator intervention.

The metal seat is also the key differentiator compared to versions with Viton or EPDM. It does not rely on an elastomer for sealing, so its hermeticity is not affected by temperature, chemical degradation, or aging. This offers a longer service life in extreme process conditions.

Metal Seat vs. Elastomeric Seat — When to Choose Metal

The selection of the seat type is also the most important criterion when specifying this check valve. The following describes cases where the CF8M metal seat is the correct choice:

• Fluids with abrasive particles: Suspended particles deteriorate rubber seats over time. The metal seat, however, resists abrasion without loss of hermeticity. Therefore, it is the standard option for fluids with solids such as pulp, slurries, or fluids with particles.
• Extreme temperatures: Elastomers like Viton have a defined thermal limit. The CF8M metal seat, however, withstands higher temperatures without degrading. Likewise, it does not deform due to frequent thermal cycles.
• Elastomer-incompatible fluids: Some solvents, concentrated acids, and specific fluids attack Viton or EPDM. In these cases, the metal seat is the only viable alternative, as CF8M offers chemical resistance without relying on a rubber seal.
• All-metal specification: In plants where the piping class requires all-metal materials without elastomers, the CF8M metal seat meets this requirement. Therefore, it is the correct component for lines with aggressive or high-purity fluids where rubber sealants are not accepted.

Construction Materials

The body is made of 316 stainless steel (CF8M), which is the standard material for industrial services with corrosive fluids. Its molybdenum content also offers greater resistance to chlorides and acids than SS304.

The swing disc is also made of CF8M, maintaining material consistency throughout the fluid contact zone. The seat is metal CF8M—without elastomers—ensuring hermeticity without chemical or thermal degradation of the seal. Finally, the spring is made of SS304, ensuring corrosion resistance and stable closing force over time.

Technical Specifications

Fluid Compatibility

This 316 SS swing wafer check valve with metal seat is compatible with demanding industrial fluids where an elastomeric seat is not viable. The main groups are described below:

• Fluids with particles or suspended solids — the metal seat resists abrasion without deterioration; therefore, it is the standard option for fluids with pulp, slurries, or particles that would damage Viton
• Corrosive chemical fluids — CF8M resists aggressive acids, bases, and solvents; likewise, the absence of elastomer eliminates the risk of chemical incompatibility of the seal
• Potable water and water treatment — SS316 resists corrosion from chlorides and disinfection agents; furthermore, the all-metal specification facilitates compliance with material regulations in contact with potable water
• Petrochemical fluids and hydrocarbons — CF8M resists hydrocarbons and petroleum derivatives; however, for fluids with very high chlorides, verify compatibility with Cematic's technical team
• HVAC systems and industrial refrigeration — prevents refrigerant fluid return without relying on an elastomer that could deteriorate; likewise, the wafer design reduces the space required for installation

Applications of the Swing Wafer Check Valve with Metal Seat

Chemical Industry

The swing wafer check valve with metal seat is suitable for systems handling aggressive chemical fluids or those incompatible with elastomers. The all-metal CF8M specification also ensures that no fluid-contacting component experiences chemical or thermal degradation. Consequently, it offers a longer service life than Viton-seated versions in environments with extremely aggressive fluids.

Potable Water and Treatment Systems

In water distribution systems and treatment plants, this valve prevents backflow. It also protects system pumps from reverse flow. The SS316 also resists corrosion from chlorides and disinfection agents. Therefore, it is a durable alternative in pumping lines where stainless steel specification without elastomers is required.

Petrochemical Industry

In installations with petroleum derivatives, CF8M also resists chemical attack from hydrocarbons. Likewise, the absence of an elastomeric seat eliminates the risk of seal degradation in fluids with solvents or aromatic compounds that could attack Viton. Therefore, this valve operates reliably in petrochemical lines where an all-metal specification is a requirement.

HVAC, Refrigeration, and Energy Systems

In HVAC, refrigeration, and power plant systems, this valve also prevents fluid return during system shutdowns. Its compact wafer design also facilitates installation in lines with space constraints. Consequently, it is the correct option when unidirectional flow retention is required without elastomers in the valve seal.

Piping Engineering — Pump Protection

In any pumping system, this valve also protects the pump from damage due to reverse flow during emergency shutdowns or electrical failures. The SS304 spring also ensures that the disc returns to the metal seat with stable closing force in each operation. Therefore, it is the standard protection component in discharge lines where an all-metal specification is required.

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Technical Data Sheet