Pressure Control Valve: How Pressure and Flow Control Valves Work

pressure control valveFor a pneumatic system to function, both pressure and flow are needed. However, the relationship between the two is often misunderstood by some. The pressure is measured in pound-force per square inch (psi), and it assesses the performance of an air compressor at any given time. On the other hand, flow is usually measured in cubic feet per minute (cfm), and is defined as the ability of an air compressor to operate consistently.

For a pneumatic system to function effectively, it needs the assistance of valves. Valves are mechanical devices that are responsible for different pneumatic operations — such as stopping, reducing, controlling, or regulating the pneumatic flow or pressure.

Valves are designed to work in specific purposes and are used in various ways. That is why they are categorised accordingly by the flow-paths they create and their number of ports. Pressure regulators, venting regulators, and needle valves are the essential devices that are present in a pneumatic system.

How Pressure Regulators Work

In a compressed air system, regulator valves are used to maintain continuous output pressure. Pressure regulators comprise actuating, control, sensing, and integral loading components, which make them a special class of valve. As the pressure moves through a pneumatic system, a pressure regulator operates with sensors to monitor its expansion.

How Venting Regulators Function

Although venting-type regulators function similarly to a pressure regulator, they also serve as a small exhaust valve that enables the release of pressure.

There are two methods to release excess pressure:

  • Internal bleeding system – the additional pressure is redirected by the venting regulator.
  • External bleeding system – a venting regulator permits the release of excess pressure out of the system.

Rather than allowing the increase of pressure, venting-type regulators serve as pressure monitors to make sure it stays at a lower level while it enters the pneumatic system and traverses through the venting-type regulator.

How Needle Valves are Used

These valves are utilised to control the flow by limiting the amount of air needed inside the pneumatic system. Needle valves feature an adjustable component to limit or decelerate the flow — this is to restrain the release of more air from the actuator, or other devices, than the system. Needle valves have a needle-like adjustable component, which can be secured into place to obstruct the actuator. Because of this, it decreases the flow of air and accumulates inside the actuator.

Master Mac 2000 is a process and pneumatic equipment distribution service provider operating in Queensland and Northern New South Wales. Established in 1989, Master Mac 2000 continues to provide top-of-the-line pneumatic equipment and process needs from quality brands such as Univer, Tolomatic, Mack, and many more.

Are you looking for a high-quality pressure control valve? Contact Master Mac 2000through (07 3344 4711) or send a quick enquiry at

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