Principle And Application Of Sanitary Stainless Steel Pneumatic Tl-type Welded Directional Control Valve

A sanitary mixproof valve with pneumatic actuation switches flow by moving the stem along its axis. Air pushes a piston that drives the stem up or down, opening one path while closing another. The TL body combines T-port and L-port geometry. The body uses SS304 or SS316L with a welded connection, gaskets in PTFE, EPDM, or NBR, a 120°C working temperature, and 10 bar working pressure.

How Axial Stem Travel Switches Flow

The actuator holds a piston and spring inside a housing. Air enters one port and pushes the piston, which moves the stem in a straight line. The stem carries a plug that seats against one of two seats in the body.

• Air drives the piston in a straight line

• Stem moves along its axis

• Plug seats against one of two seats

• Port pair switches with each stroke

Double-Seat Isolation for Mixproof Duty

Two seats separate the flow paths. When the plug seals one seat, the other path stays isolated. This keeps two fluids apart even during the switching stroke.

TL Port Geometry and Flow Routing

The TL body carries three ports. A T-port bore links one inlet to two outlets at once. An L-port bore links two adjacent ports and blocks the third.

Combining both patterns in one body lets the valve divert, merge, or reverse flow. A mixed proof valve built this way replaces two separate shutoff valves on a shared manifold.

Actuator Control and Fail-Safe Behavior

A solenoid pilot valve directs air to the actuator ports. A spring-return actuator closes the valve on air loss. A double-acting actuator holds position instead.

The choice follows the safe state for the process. On a line that must isolate on failure, spring return keeps the paths separated.

Position Feedback and Control Signals

A position sensor on the actuator reports the stem state to a control cabinet. That signal confirms which path is open before the next step in the sequence starts.

Welded Installation and Maintenance

1. Confirm the weld end matches the line size and schedule.

2. Align the body for straight flow through the active ports.

3. Weld the body to the line and grind the seam flush.

4. Connect air supply through a filter regulator.

5. Stroke the valve through both positions before pressurizing.

A mixproof valves body welded into the line cannot be removed without cutting pipe. Seat and plug access comes from the bonnet side, so the actuator lifts off for service.

Common Applications

Pneumatic reversing valves serve lines that switch between product, water, and cleaning fluid. The mixproof seats keep the streams apart during the switch.

• Dairy raw milk and CIP routing

• Brewery transfer and cleaning circuits

• Pharmaceutical batch separation

• Beverage syrup and water blending

• Food processing drain lines

A mixproof valve with a TL body suits manifolds that route several fluids through shared piping. The pneumatic drive allows remote or timed switching.

Gasket Selection by Medium

Gasket choice follows the product and cleaning cycle. EPDM handles steam and water service. NBR suits oil and fuel duties where EPDM swells. PTFE covers broad chemical resistance at higher cost. A gasket that swells or hardens loses compression and lets fluid cross a closed seat.

Sanitary Stainless Steel Pneumatic TL Type Welded Divert Valve

• Pneumatic seat valves conbined a piston within a cylinder, ball housing, stem, and connected end parts and are developing to various flowing types such as F type and others like LL, TT, LT, Y, T, L, TL....

• The divert valves can be working automatically by air in case of the valves are equipped with CSEs control boxes which are designed for signal transfer or individually valve working control.A piston valve is a device used to control the motion of fluid in tube according to linear motion of a piston within a cylinder.

Technical Data

Product Parameter

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