Sanitary Weld Check Valve in 316L Stainless Steel — Viton

Cematic's 316L stainless steel sanitary weld check valve ensures unidirectional flow in demanding sanitary systems. Its design combines butt-weld ports—which eliminate leaks and dead zones—with a clamp-removable body.

This allows for inspection, cleaning, and replacement of the Viton seal without special tools. Therefore, it is the correct solution for the food, pharmaceutical, cosmetic, and chemical industries. In these sectors, reflux control and hygiene are non-negotiable requirements.

Its Viton seat also withstands temperatures up to 180 °C and a wide range of chemical agents. Consequently, it guarantees a hermetic and long-lasting seal even under extreme process conditions.

Principle of Operation — Sanitary Weld Check Valve

The sanitary weld check valve operates automatically and without external actuation. When the fluid flows in the correct direction, the pressure overcomes the spring force, thus opening the disc and allowing passage.

When the flow ceases, however, the spring returns the disc to the Viton seat. The valve closes immediately and automatically, thereby protecting the line against any fluid return without operator intervention.

The butt-weld ports also eliminate leak points and dead zones that exist in clamp or threaded connections. For this reason, they are the preferred type of connection in CIP/SIP systems and aseptic processes where circuit integrity is critical.

The Differentiating Advantage — Weldable with Removable Body

This valve combines the advantages of two connection systems that usually exclude each other:

• Weldable ports: The connection to the pipe is permanent and without external gaskets, thus eliminating all possible leak points in the connection. Consequently, it is the preferred type of connection in high-purity aseptic lines where external contamination is unacceptable.
• Removable body with clamp: Despite the welded connection to the pipe, the valve body can also be completely disassembled using the clamp. Therefore, inspection, cleaning, and replacement of the Viton seal are performed without cutting or modifying the pipe. Likewise, maintenance time is significantly reduced compared to check valves with non-removable bodies.

Construction Materials

The body is made of 316L stainless steel, which is the standard material in demanding hygienic applications. Its molybdenum content also offers greater resistance to chlorides and CIP agents than SS304. The disc is also made of SS316L, maintaining material consistency throughout the fluid contact area.

The seal is made of Viton (FKM), which is compatible with temperatures up to 180 °C. It also resists acids, alkalis, and CIP agents that would degrade NBR or EPDM. Finally, the Ra ≤ 0.8 µm internal finish is the sanitary standard that eliminates surface roughness where microorganisms or product residues could accumulate.

Technical Specifications

Fluid Compatibility

This sanitary weld check valve with Viton seal is compatible with the most demanding fluids in the sanitary industry. The main groups are described below:

• Purified water and water for injection (WFI) — SS316L does not contribute metallic ions; therefore, it is the standard material in high-purity pharmaceutical water distribution systems.
• Food fluids — milk, juices, beer, wine, oils — SS316L and Viton meet food contact requirements; additionally, the Ra ≤ 0.8 µm finish prevents residue retention between batches.
• CIP agents — caustic soda, nitric acid, peracetic acid up to 180 °C — Viton resists the most aggressive CIP agents at temperature; likewise, welded ports prevent leaks during pressurized cleaning cycles.
• Clean steam up to 180 °C — Viton maintains its sealing properties at SIP sterilization temperature; in contrast, EPDM or NBR would be limited to 80-110 °C.
• Cosmetic fluids — creams, lotions, shampoos — SS316L and Viton do not contribute contaminants to the product; however, for viscous fluids, verify the minimum differential opening pressure with Cematic's technical team.

Applications of the Sanitary Weld Check Valve

Food and Beverage Industry

The sanitary weld check valve prevents reflux in production lines for milk, juices, beer, wine, and oils. The welded ports also eliminate leak points at the connection and ensure circuit integrity during CIP cycles. Consequently, the line returns to production faster and with a lower risk of cross-contamination between batches.

Pharmaceutical Industry

In production lines for liquid medicines, serums, and solutions, this valve also meets the high standards of cleanliness and chemical resistance required. The removable body also facilitates inspection and replacement of the Viton seal in the shortest possible time without cutting the pipe.

Therefore, it is the correct component in validated GMP aseptic lines where welded circuit integrity is mandatory.

Cosmetics and Personal Care

In the production of creams, lotions, and shampoos, this valve also ensures that the fluid does not return upstream between cycles. Its internal finish Ra ≤ 0.8 µm also prevents the retention of cosmetic residues in the valve area. Consequently, formulation changes are cleaner and safer between production batches.

Steam and High-Purity Liquid Systems

In systems with clean steam and purified water, welded ports eliminate mechanical gaskets. These, in contrast, are risk points for contamination in other connections. The Viton seal also resists steam up to 180 °C in SIP cycles without premature deterioration. Therefore, this valve is the standard retention component in purified water and clean steam circuits in pharmaceutical and food plants.

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Technical Data Sheet