Seeing a pressure drop from your compressor

Pressure is a measure of force per unit of area measured in bar(g) or psi (pounds per square inch).  Downstream air tools powered by portable compressors often have specific air pressure and flow requirements and so it is important that the right compressor is selected in order to minimise any downtime or productivity issues.

A common problem seen by compressor users is that of the pressure drop.  This can be frustrating and occurs when the expected pressure output from the compressor does not reach the end use tool.  This can affect performance of the tool but it can also mean that the compressor fails to reach its normal cut out pressure and so therefore runs for longer periods of time than intended.  If the compressor is not rated for 100% duty cycle use (in other words is not capable of continuous running) then it can lead to overheating problems and potentially long-term damage, not to mention higher energy use.

To compensate for pressure levels dropping, users often try to increase the air flow levels from the compressor but this can waste energy.   Finding the root cause of the pressure drop problem is therefore important.

Here is our handy list of potential pressure drop culprits in a portable compressor

  1. Check the air line from the compressor to the air powered tool – Leaks in the air line from the portable compressor to the tool will mean an inevitable loss of pressure which can affect the productivity of your equipment. This is always a good place to start any checks, as it can be the simplest to rectify.   If a pressure drop occurs when the compressor is initially installed it may be a sign that the airline is too long between the compressor and the air powered tool, therefore increasing the diameter of the pipe or shortening the airline (if that is possible) will rectify the problem.
  2. Check the air tank and any fittings for air leaks as these will lead to reduced pressure reaching the air powered tool. It is also important to check any drain valves are sealed properly as these can also be a root cause of any drop in pressure.
  3. Check for blockages in the lines to filters. Blockages to the lines may only inhibit a small part of the overall air flow from the compressor, but this can still result in a major pressure loss.  Pressure tends to increase in front of an obstruction and then significantly decrease as the air passes by it.  It is unlikely that any obstructions would completely stop the air flow as most compressors would quickly and safely shut down as a result of the pressure build up.
  4. Check line filters have been replaced according to the maintenance schedule. These can clog with dust or dirt if not replaced frequently enough and impede air flow. Regular servicing and maintenance can minimise any pressure drops occurring.
  5. If a regulator is fitted, check that it is operating correctly and is not faulty. Regulators are connected to compressors to ensure consistency of flow for particular applications.  These can only ever reduce the pressure from a compressor, not increase it.  If there is a fault with the regulator or it has not been maintained properly then it can result in an unexpected and excessive pressure drop.

How to reduce pressure drops occurring:

  • Ensure that the right compressor and air lines are used for the job.
  • Operate and regularly maintain the compressor, air filters, drying equipment and regulators according to the service schedule.
  • Ensure that any after coolers, separators, dryers and filters are selected to have the lowest possible pressure drop for the application.
  • Minimise the distance the air travels from the compressor to the end use application.

Regularly checking your compressor and sticking to a routine maintenance schedule can make a big difference to the productivity of your air powered equipment as well as your portable compressor.  If you are experiencing pressure drops and can’t get to the bottom of the problem then drop the Vert team a line at [email protected]