Principles And Selection Guide For Double-sealed Valves

A mixproof valve suits food and beverage lines that handle multiple products, recipes, or cleaning fluids. Its dual-seat structure separates process paths with independent seals and a leakage chamber, reducing direct cross-flow during transfer and batch changeover.

Why Double-Seat Separation Matters

Shared piping can carry different products during one production cycle. Mixproof valves create a separation zone between media, reducing the risk of one product entering another process path.

Main Functions

A double-seat design can provide:

• Independent sealing between process paths
• A leakage chamber for separation and detection
• Controlled product transfer
• Defined isolation during changeover
• Support for CIP routing

This design suits systems where product and cleaning circuits share common piping.

How a Mixproof Valve Works

A mix proof valve uses two sealing areas to separate connected process paths. When closed, the leakage chamber remains between the two seats. If a seal fails, leakage can enter the chamber and follow the designated outlet.

A double seat mixproof valve therefore provides a different separation principle from a standard single-seat shutoff valve.

Operating States

• Closed: process paths remain separated.
• Open: the selected flow path is connected.
• Leakage: fluid enters the chamber for detection.

The actual sequence depends on valve design and control logic.

Where Mixproof Valves Fit

A mixproof valve suits production lines with frequent product changes and shared equipment.

Common Applications

• Dairy processing
• Beverage production
• Juice and liquid food lines
• Mixing and blending
• Tank transfer
• Product and CIP separation

The valve is suited to points where different media must remain separated during production and cleaning.

Batch Changeover and CIP

Different recipes may pass through the same piping system. The valve should keep the product route isolated while allowing the cleaning route to operate according to the process sequence.

Mixproof valve operation depends on seat movement, pressure difference, leakage-chamber design, and the validated CIP procedure.

Conditions to Check

Product viscosity, flow direction, pressure difference, cleaning temperature, chemical compatibility, switching frequency, and drainage all affect valve performance.

Construction and Selection

Sanitary systems commonly use stainless steel wetted parts and hygienic seals. Valve size, seat material, connection, actuator, and cleaning requirements should match the process.

The complete valve assembly should be evaluated rather than selecting only by pipe size.

Mix Proof Valve vs. Standard Shutoff

A mix proof valve provides dual-seat separation between process paths. A standard butterfly or ball valve mainly provides line isolation and does not create the same leakage chamber.

This difference matters when products and cleaning fluids share one process system.

Selecting the Right Configuration

The selection process should follow the production sequence:

1. Identify all product, cleaning, and utility streams.
2. Define which media must remain separated.
3. Confirm pressure, temperature, flow direction, and CIP conditions.
4. Select seat, seal, connection, and actuator requirements.
5. Verify drainage and leakage detection.

The selected configuration should match the process diagram and batch changeover procedure.

Why Mixproof Valves Suit Multi-Batch Production

Mixproof valves combine dual-seat separation with controlled process routing. This structure suits food and beverage systems that alternate between products and cleaning fluids while maintaining separation during transfer and changeover.

For shared production lines, the valve configuration should be selected around the required separation, cleaning sequence, and actual process conditions.

Sanitary Pneumatic Double Seat Clamped Mixproof Valve

• When the valve is opened, the fluid can pass from one body to the other.

• Once the valve is closed, the double seat creates an annular chamber that isolates the dodies sealing them with double seals. It allows a CIP operation providing an interface between the two fluids, preventing the possibility of product contamination.

• Due to the leakage detector any leak of a seat seal is detected by the apprearance of liquid at the bottom of the valve. The zone between the poppets and the seats is cleaned by pulsing the individual poppets when the specific line is being cleaned, the poppets are fractionally stroked by two additional limited movement pistons located within the main actuator.

• Applied for production of beer, beverage, food, pharmacy, etc, such as, syrup, yogurt, portridge.

Technical Data

Product Parameter

Product Pictures