What is the function of volume booster?

A volume booster is a pressure regulation device that uses a pilot pressure instead of a spring or adjustable thread like an air pressure regulator.

A volume booster may alternatively be referred to as a “pilot operated regulator”. A regulator’s spring generally provides the mechanical pressure necessary to open the supply valve till the output pressure & spring force are balanced. In a volume booster, rather of a spring providing force balance, a pilot pressure operating on a diaphragm provides the “spring force”. A volume booster circuit consists of four main air components:

• Supply Pressure

• Regulated or downstream pressure.

• Signal (pilot), Pressure, and

• Atmosphere (exhaust).

A regulator, I/P transducer, valve positioner, or other pressure modulating device can provide signal or pilot pressure. The primary function of a volume booster is to pump a large volume of air downstream at a specific pilot pressure. The pilot pressure might affect the output pressure. Volume boosters are generally employed in the following applications:

• To accelerate the stroke of larger-volume actuators.

• Air-powered, remote pressure regulation.

• Hazardous settings in which electric signals are undesirable.

Some popular volume booster options include the inclusion of a bypass valve (bypass needle valve), which can be used to regulate the dynamic response to ensure steady performance over a wide range of applications. Another alternative is to add an adjustable bias to skew output pressure away from the signal pressure. However, this is frequently observed in smaller forms of volume boosters, also known as air relays. This could indicate a positive (or) negative bias. Other alternatives include diaphragm materials designed for caustic and low-temperature conditions.

Application of Volume Booster

• Typically, the volume booster is positioned between the positioner & the actuator. A supply pressure regulator filters the supply air and maintains a steady supply pressure. This method, the volume booster provides the actuator with an air flow output with a pressure that is identical to the positioner’s signal pressure, but with a substantially larger volume.

• In conjunction with a solenoid valve it can be placed across the volume booster & the actuator. In this situation, the solenoid valve should be sufficiently large to utilize the volume booster’s entire air capacity.