Flow Control

Type VF Flanged Ends	Type VM Threaded Union Ends	Type VMP-Compact Threaded Socket Ends

The direct air operated AKO pinch valve is your most practical solution for ON/OFF or proportional flow control of abrasive, corrosive and fibrous products including granules, powders and slurries.

All of the AKO pinch valves, including the types VF Flanged Ends, the VM Threaded Union Ends and the VMP Compact Threaded Socket Ends can be furnished for proportional flow control.

In addition to either fully closed or fully open position the AKO pinch valve can be used for flow control by utilizing a compact electronic pressure regulator. This regulator converts the customer’s electrical input signal of either 4 - 20 mA or 0 - 10 VDC into a proportional pneumatic pressure output. The variable output pressure allows the sleeve to be set at partially open position and adjust the flow rate in proportion to the input signal.

The electrical input signal is provided from the customer’s control panel and causes regulation of the pressure of the compressed air supply to the pinch valve. By using a simple set point device, such as a potentiometer to control a voltage signal from 0 - 10 VDC, the pinch valve is manually controllable and can be set to any position between fully open and fully closed.

Each valve consists of a seamless elastomer sleeve enclosed in the valve body which eliminates valve stem packings or seals of conventional valves which can wear out and leak.

The sleeve consists of a special fabric reinforced elastomer designed for high spring back elasticity to assure quick response to the applied control pressure over the full range from fully closed and bubble tight shutoff to fully open.

Principle of Operation:

When compressed air or a suitable fluid, at approx. 30 psi above line pressure, is applied to the valve body the sleeve in the valve will be closed proportional to the input signal, from fully open to fully closed, or “pinched off”, and when fully closed forming a tight seal even on fibrous and or granular materials.

When the external pressure on the sleeve is released the sleeve will respond quickly and open up to a position proportional to the applied control pressure.

Advantages:

• Free passage of solids in either direction and no plugging
• Complete shut-off with liquids and suspended solids
• No packing, seals or bearings required
• Light weight, easily maintained
• Negligible pressure drop
• Only one wear part
• Self cleaning

Sizes Available and Materials of Construction:

For sizes available and Materials of Construction please refer to the data listed for each Type of Valve:

• Type VF Flanged Ends
• Type VM/VMF Threaded Union Ends
• Type VMP-Compact Threaded Socket Ends

Pinch Valve Operating Conditions:

Please refer to the individual data sheets for each type of valve as listed above under “Sizes available and Materials of Construction”.

Pinch Valve Accessories:

To operate and control the pinch valve a wide assortment of accessories is available including

• Solenoid air valves
• Pilot air valves
• Quick exhaust valves
• Exhaust mufflers
• Pressure regulators
• Regulator/filter units
• Proportional pressure regulators

Pinch Valve Applications:

• Food
• Water
• Chemical
• Agriculture
• Pharmaceuticals
• Powder painting systems
• Sewage and Water treatment
• Power plants and coal slurries
• Cement, lime and aggregate plants
  and for any material streams where flowables such as liquids, pastes, slurries, powders, granules, pigments and other materials are pumped, blown, pushed, metered or flow by gravity through pipelines and require proportional flow control.