matiriel-accessoires/controle-de-debit/vannes-a-piston-pneumatiques

+212 523 361 588 info@wepack-machinery.com Location

Pneumatic piston valves

Flow control solutions for fluid systems

Pneumatic piston valves are valves that allow the piston to cut off or open the flow by a linear movement away from its seat thanks to the pneumatic power supplied to the actuator.

Operation: Default position

Materials: AISI 304/316 stainless steel

Supply pressure: 4 to 7 bar

Request a quote

Main characteristics of pneumatic piston valves

Operates in the closed position by default with a safety spring
Excellent seal for a complete closure
Linear piston movement for precise flow control
Long service life and operational reliability
Robust design for demanding industrial environments
Reduced maintenance and reliable operation
Fast response time for automatic control

Operating principle

Our pneumatic piston valves are manufactured in the closed position. As long as no air is supplied to the actuator, the valve remains closed due to spring force, thus preventing fluid flow. When compressed air is applied to the actuator, the piston moves linearly away from its seat, allowing the flow to open.

The linear movement of the piston provides precise flow control and excellent sealing even after numerous opening and closing cycles. These valves are particularly well-suited for applications requiring automatic control and enhanced safety thanks to their default closed position.

Types of pneumatic piston valves available

Connection type: Flanged – Threaded

Outer body of the piston: AISI 304 stainless steel

Valve body: AISI 316 stainless steel

Piston: AISI 316 stainless steel

Operating temperature: 220 °C

Piston supply pressure: 4 to 7 bar

Main variants:

Pneumatic piston valve with flange (316 stainless steel body)
Piston gear valve (316 stainless steel body)
Valves with different connection sizes
Emergency manual control options
Normally closed or normally open configurations
Valves for high temperature applications

Industrial application areas

Agrifood

Hygiene, safety, and process efficiency are paramount in the food and beverage industry. Our easy-to-clean and hygienic stainless steel solutions ensure safe operation across a wide range of production lines, from dairy and beverages to fruit juice and beer production.

Automobile

In the automotive industry, temperature control and fluid management are essential in processes such as production lines, testing systems, and paint applications. Our compact and robust equipment ensures energy efficiency and operational continuity in these processes.

Marine

Marine applications demand equipment that can withstand extreme environmental conditions and has a long service life. Our saltwater-resistant, low-maintenance solutions reliably provide cooling, heating, and fluid control in ship systems.

HVAC

Efficiency and longevity are essential for air conditioning and domestic hot water systems. Our heating, cooling, ventilation, and domestic hot water solutions optimize energy savings and system performance in the building sector.

Petrochemical and Pharmaceutical

These industries require equipment capable of withstanding high temperatures and pressures. They also require system solutions that can handle corrosive and aggressive gases and liquids. We offer robust structures that meet these requirements, thus ensuring process safety and continuity.

Metallurgical industry

Systems subjected to high temperatures and pressures during metalworking processes require durable and long-lasting solutions. Our products, which guarantee reliability and process stability on industrial production lines, optimize productivity.

Energy

Efficiency is crucial for power generation, cogeneration, and heat recovery systems. Our high-performance solutions help reduce energy costs while ensuring the sustainable operation of these systems.

Textile

Temperature control and energy efficiency are essential in processes such as printing, dyeing, finishing, and drying. Our solutions, specifically designed for textile production processes, improve operational efficiency and optimize energy consumption.

Technical advantages of pneumatic piston valves

• Closed position by default for increased safety

• Excellent sealing even after numerous cycles

• Precise flow control via linear movement

• Fast response time for automation

• Stainless steel construction for reduced corrosion

• Reduced maintenance and long lifespan

• Compatible with many industrial fluids and gases

• Standard supply pressure 4-7 bar

• Operating temperature up to 220°C

• Flanged or threaded connection options

Frequently Asked Questions

Frequently asked questions about pneumatic piston valves

In a pneumatic piston valve, the compressed air supplied to the actuator (4 to 7 bar) lifts the piston, moving it away from the seating surface and opening the passage. When the air supply is cut off, the force of the internal spring pushes the piston back, thus closing the valve. This non-closing (NC) design provides protection against air leaks and enhances process safety.

The AISI 316 stainless steel body and piston, combined with the AISI 304 stainless steel outer casing, are perfectly suited for use with corrosive fluids, in food and beverage and sanitary systems, with steam/condensate, and in chemical applications. Sealing and mechanical stability are guaranteed up to 220°C. The choice of material and seal (PTFE, graphite, etc.) ensures chemical compatibility and a long service life.

Flanged and threaded connection options ensure compatibility with the pipeline architecture. Concentric and stress-free alignment of the valve axis with the pipe, the absence of external loads on the body, and installation in the direction of flow (arrows) protect the sealing surface. Horizontal or vertical installation is possible; it is recommended to avoid condensation pockets and provide drainage/air venting points.

Neumatic piston valves excel primarily in fast and stable start/stop operation. For continuous control, modulation can be achieved by using them in conjunction with a positioner; in this case, a stroke feedback (limit switch/4-20 mA transmitter), a NAMUR solenoid valve, speed variation recording, rapid drain, and air conditioning with FRL (filter-regulator) are added. For safety reasons, automatic spring closure is standard.

The valve diameter must be chosen based not only on the pipe diameter, but also on the required coefficient of friction (Kv/Cv), the differential pressure, and the desired flow rate; an oversized valve will operate erratically, while an undersized valve will increase pressure losses. The actuator force is determined with a safety margin of at least 25% to ensure secure seat closure under differential pressure. A stable, dry air supply between 4 and 7 bar ensures optimal stroke times and repeatability.