Pressure Relief

The reliable and economic solution to protect your pump and piping systems from excessive pressure.

The AKO pressure relief system consists of a standard pinch valve in combination with a pressure regulator controlling the air pressure applied to the flexible sleeve.

The pinch valve is installed in a bypass line and the valve control pressure is set so that the pinch valve is closed for the normal operating conditions of the system. During an upset condition of the system, causing a pressure rise such as a clogged pump or blockage in the pipeline, the increased pressure forces the sleeve to open which provides a pressure relief until the cause of the increased pressure is removed. When the blockage is cleared the pinch valve sleeve will again return to it’s original closed position and normal flow is re-established in the system.

The direct air operated AKO pinch valve is a cost effective and practical solution for controlling damage to system components from excessive pressures in the piping system.

The valve consists of a seamless elastomer sleeve enclosed in the valve body and, depending on type of valve, held in place by either two bolted end flanges or threaded socket ends.

The enclosed body design 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 for variable pressure conditions.

Principle of Operation:

When compressed air or a suitable fluid, at approx. 30 psi above line pressure, is applied to the valve body the valve can be fully closed, or “pinched off”, forming a tight seal even on fibrous and or granular materials.

Upon increase of (internal) system pressure the sleeve is forced open providing pressure relief. When the internal system pressure, forcing the sleeve open, returns to normal the sleeve is again forced closed by the set control pressure.

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 pressure relief applications.

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 variable pressure conditions.

Advantages:

• Protects pumps and motors from damage
• Free passage of solids and no plugging
• No need to reset after pump startup or pressure surges
• Automatic reset of the valve once blockage is cleared
• Complete shut-off with liquids and suspended solids
• No mechanical parts to cause clogging or blockage
• No packing, seals or bearings required
• Light weight, easily maintained
• Only one wear part

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:

Where ever flowables such as liquids, pastes, slurries, powders, granules, pigments and other materials are pumped, blown, pushed, metered or flow by gravity through pipelines, including -

• Food
• Water
• Chemical
• Agriculture
• Pharmaceuticals
• Pneumatic conveying
• Powder painting systems
• Ceramics, glass and plastics
• Sewage and Water treatment
• Power plants and coal slurries
• Cement, lime and aggregate plants
• Mining sludges, sand and waste liquids
  and many other material streams