Pressure Fluctuation

Pipe Maze

So there are locations in your compressed air system that the pressure just seems to fluctuate? With the maze of pipes, you have to consider pressure drop for certain areas. Most clients compensate for low or fluctuating pressures with a common fix: Raise the compressor output pressure. While this will usually solve the low pressure problem it rarely solves fluctuation and in addition it also increases your cost of power to produce higher pressure air. The input power for a compressor increases 1% for every 2 PSIG in pressure elevation!  So what’s a plant to do?

Pressure/Flow Controllers

Pressure/Flow Controllers (P/FC) are system pressure controls that can be used in conjunction with the individual and multiple compressors. A P/FC does not directly control a compressor and is generally not part of compressor package. A P/FC is a device that serves to separate the supply side of a compressor system from the demand side, and requires the use of storage. Controlled storage can be used to address intermittent loads, which can affect system pressure and reliability. The goal is to deliver compressed air at the lowest stable pressure to the main plant distribution system and to support transient events as much as possible with stored compressed air. In general, a highly variable demand load will require a more sophisticated control strategy to maintain stable system pressure than a consistent, steady demand load.

“Credit to the US DOE for the preceding paragraph”

Contact a compressed air professional to discuss your particular low or fluctuating pressure concerns.

Get in Touch

Utilizing Compressed Air Storage

If you look at most any industrial compressed air system you will find a receiver located somewhere in the layout. However, just having a receiver does not mean the system is fully utilizing the capability of the storage.

Air Receiver

 

Properly utilized compressed air storage should allow a compressed air system to meet its peak demand needs and help control system pressure without starting additional compressors. The correct type and quantity of air storage depends on air demand patterns, air quantity and quality required, and the compressor and type of controls being used. An optimal air storage strategy will enable a compressed air system to provide enough air to satisfy temporary air demand events while minimizing compressor use and pressure.

To properly utilize the stored compressed air the pressure in the receiver needs to be stored at a higher pressure than the system pressure. The strategy is to allow the differential between these 2 pressures to be sustained by incorporating a pressure flow controller (PFC) and/or metering valves.

This allows the pressure in the demand side to be reduced to a stable level that minimizes actual compressed air consumption. PFCs are added after the primary receiver to maintain a reduced and relatively constant system pressure at points of use, while allowing the compressor controls to function in the most efficient control mode and discharge pressure range. Properly applied, a PFC can yield significant energy savings in a system with a variable demand load.

A professional air audit can determine the proper storage size requirements.

Get-in-Touch.png