What Are The Common Connection Methods for Sanitary Check Valves?

The primary function of a sanitary check valve (also known as a one-way valve or non-return valve) is to prevent fluid backflow and protect upstream equipment (such as pumps and 

metering tanks) from backflow contamination. In the food, dairy, and pharmaceutical industries, the design of its connection method also follows the core principles of no dead angles

, easy disassembly, and easy cleaning.

There are four common connection methods, each with its own focus, suitable for different installation locations and process requirements:

1. Clamp-on Quick-connect Type

This is the most common and flexible connection method in sanitary piping, and the first choice for most factories.

Structural Features: The valve body has clamps at both ends, connecting to the pipeline via clamps, gaskets, and nuts.

Advantages:

Extremely quick disassembly and maintenance: Disassembly is possible without special tools, facilitating regular checks of valve disc sealing, 

internal cleaning, or replacement of internal springs/gaskets.

Highly flexible:Installation position can be adjusted at any time, suitable for pipelines requiring frequent disassembly and cleaning.

Disadvantages:

Gaskets are consumables and require regular replacement under prolonged high temperatures.

Applicable Scenarios: Most daily production pipelines, especially interfaces requiring frequent disassembly and cleaning(such as inlets and outlets).

2. Welded Type

This is the highest level of hygiene and the most permanent connection method, suitable for applications requiring the highest sterility.

Structural Features: The valve body is directly butt-welded to the pipeline at both ends.

Advantages: 

Absolute sealing: No gaskets or threaded gaps, completely eliminating leak points and the possibility of microbial growth.

Highest Cleanliness: The inner wall is completely smooth, with no risk of residue.

Disadvantages:

Difficult Maintenance: If internal check components (such as valve discs or springs) are damaged, the valve must be cut off from the pipeline for 

replacement or repair.

High Installation Requirements: Requires professional argon arc welders for welding and passivation.

Applicable Scenarios: Aseptic filling lines, high-purity water systems, and stationary permanent pipelines.

3. Threaded (Union) 

This connection method is relatively rare in sanitary applications, but is still seen in small-diameter or specific equipment connections.

Structural Features: The valve body has internal or external threads at both ends, which are tightened to the threaded fittings on the pipeline. 

Sealing tape or sealant is usually used to fill the thread gaps.

Advantages:

Easy Installation: No welding or clamps required, simply tighten.

Low Cost: Relatively low processing costs.

Disadvantages:

Existing Sanitary Dead Zones: Thread gaps are difficult to clean thoroughly, easily trapping dirt and bacteria.

Not recommended for aseptic areas: Threaded connections are generally not permitted for process piping that comes into direct contact with 

finished products during stringent hygiene reviews.

Suitable scenarios: Instrument interfaces, sampling ports, vents, or auxiliary pipelines that do not come into contact with food.

4. Flanged Type

An option for large-diameter or high-pressure applications, but less common than the previous three types in sanitary small-diameter piping.

Structural features: The valve body has flanges at both ends, connecting to the pipe flange via bolts and gaskets.

Advantages: 

High strength: Suitable for large diameters (e.g., DN150 and above) or high-pressure applications.

Easy disassembly: Can be removed entirely by unscrewing the bolts.

Disadvantages: 

Bulky: Takes up a lot of space and is costly.

Potential dead zones: Gaps may form if the gasket is not installed properly.

Suitable scenarios: Inlets and outlets of large storage tanks, pump or equipment interfaces connected to flanges

Summary and Selection Recommendations