Pneumatic On-Off Control Valves
Pneumatic on-off control valves are automatic valves that move to fully open or fully closed with control air. Two designs stand out in this group: piston-actuated angle seat Y-type valves, and ball and butterfly valves with rotary pneumatic actuators.
In the Y-type valve, the spring-loaded piston lifts the plug off the seat when air is applied; when air is removed, the spring closes the valve, so the valve is normally closed. For the ball types, the body material is chosen as stainless steel, brass, cast steel or U-PVC to suit the medium.
Main Applications
- Steam and hot water isolation on textile dyeing and printing machines
- Programmed open-close on food and beverage filling lines
- Clean water and steam lines in pharmaceutical and medical equipment plants
- Reactor feed and discharge in chemical plants
- Process water control in paper and iron-steel plants
- Automated U-PVC valves in pools and water treatment
Technical Data
| Y-type size range | DN15–DN50 (G1/2–G2) |
|---|---|
| Y-type connection | Threaded (G / BSP) |
| Y-type max. working pressure | 16 bar |
| Y-type max. temperature | 180 °C |
| Y-type control air | 3–8 bar |
| Y-type Kv values | G1/2: 4.7 · G3/4: 9.5 · G1: 18.1 · G1 1/4: 23.1 · G1 1/2: 32.9 · G2: 52.8 m³/h |
| Y-type actuator diameter | 50 mm (G1/2–G3/4) · 63 mm (G1) · 90 mm (G1 1/4–G2) |
| Y-type operation | Single acting, spring return, normally closed |
| Media (Y-type) | Water, hot water, steam, LPG and pressurised gases, gases such as oxygen, hydrogen and nitrogen, various chemicals |
| Ball valve bodies | Stainless steel (PN63 / PN40), brass (PN40), cast steel (PN40), U-PVC |
| Rotary actuator control air | 2.5–8 bar (single acting type), depending on model |
| Installation | Flow direction per body arrow; any position, with the indicator visible |
Material Options
| Part | PN16 · stainless Y-type | PN40 · brass ball | PN40 · cast steel ball | U-PVC ball |
|---|---|---|---|---|
| Body | Stainless cast CF8M | Brass | Cast steel | U-PVC |
| Closing element | Valve plug CF8 | Ball, depending on model | Ball, depending on model | Ball, depending on model |
| Seat | PTFE | Depending on model | Depending on model | Depending on model |
| Stem | Stainless AISI 304 | Depending on model | Depending on model | Depending on model |
| Stem sealing | PTFE packing (3 stages) | Depending on model | Depending on model | Depending on model |
| Actuator | Piston type; body CF8, aluminium piston, FPM piston ring, NBR O-ring | Rotary pneumatic actuator | Rotary pneumatic actuator | Rotary pneumatic actuator |
| Spring | 65Mn spring steel | By type (single / double acting) | By type (single / double acting) | By type (single / double acting) |
Y-type valves are preferred in machine applications needing high cycle counts with steam, hot water and viscous media; ball types are preferred on water, gas and chemical lines needing full bore. Choose a U-PVC body for aggressive chemicals and a stainless or cast steel body for high pressure.
Advantages
Normally Closed Safety
- In the Y-type the spring closes the valve when air is lost.
- Flow stops during a power outage.
Steam Capable
- Y-type with PTFE seat up to 180 °C.
- Used on steam, hot water and pressurised gas lines.
Wide Body Choice
- Stainless, brass, cast steel, U-PVC.
- The right material for medium and pressure.
Visual Check
- Nylon position indicator on the Y-type.
- Open-closed status is visible on site.
Construction and Design Features
- Y-type: angle seat CF8M body, spring-loaded piston actuator
- Y-type: PTFE seat and three-stage PTFE stem packing
- Ball type: rotary pneumatic actuator with ISO 5211 top flange and full-bore ball
- Remote operation via solenoid valve and limit switch box
- Body arrow showing flow direction
Request a quote for pneumatic on-off valves by stating medium, temperature, pressure, connection size, control air pressure and solenoid voltage.
How to Choose?
- Choose the valve designY-type for steam and high-cycle machine lines; pneumatically actuated ball valve for full-bore lines.
- Check the flow coefficientCalculate the Kv needed for the flow; for the Y-type it is 4.7 for G1/2 and 52.8 m³/h for G2.
- Confirm control airY-type valves need 3–8 bar air; use an air preparation unit for air quality.
- Specify the body materialStainless for steam and food, brass for water and gas, cast steel for high pressure, U-PVC for chemicals.
Complementary Products
Why ORFA?
Other On-Off Control Valves
Our Pneumatic On-Off Control Valves
ORFA supplies pneumatic on-off control valves in a range of pressure classes, sizes and connection types to suit your application. Descriptions, technical specifications, materials and dimension tables are available on each detail page.
Pneumatic Actuated Ball Valve
Pneumatic actuated ball valve: single/double acting actuator, 2 and 3-piece stainless, flanged and brass body, ISO 5211/NAMUR, DN15–DN200, PN16–PN63.
Details →Pneumatic Angled Piston Valve
Pneumatic angled (Y/L type) piston valve: AISI 316 stainless body, EPDM or PTFE sealing, hose tail or threaded, various piston sizes. Steam, water and process automation.
Details →Get a quote for your project
Our sales team will prepare the best solution for your needs.