Proactive leak detection and repair save energy

Proactive leak detection and repair can reduce air leaks in an industrial compressed air system that sometimes waste 20-35% of a compressor's output to less than 10% of compressor output.

Air leaks can be a significant source of wasted energy in an industrial compressed air system, sometimes wasting 20-35% of a compressor's output.

A typical plant that has not been well maintained will likely have a leak rate of about 15% to 25% of total compressed air production capacity.

On the other hand, proactive leak detection and repair can reduce these leaks to less than 10% of compressor output.

In addition, to being a source of wasted energy, air leaks also contribute to other operating losses.

Air leaks cause a drop in system pressure, which can make air tools function less efficiently, thus affecting production.

As well as that, by forcing the equipment to turn/cycle more frequently, leaks shorten the life span of almost all system equipment, and indeed including the compressor itself.

Increasing the running time can also lead to additional maintenance requirements and increased unscheduled downtime.

Finally, air leaks can lead to adding unnecessary compressor capacity.

Air leakages can come from any part of a system, however, the most common areas are within: a.

Couplings, hoses, tubes, and fittings, b.

Pressure regulators, c.

Open condensate traps and shut-off valves, and d.

Pipe joints, disconnects, and thread sealants.

(Energy Efficiency web site www.energy-efficiency.org states: "Compressed air; A 5-mm diameter hole in an airline costs around GBP 1,400 per year." The best way to detect leaks is to use a EP542A ultrasonic acoustic detector fro Logis-Tech Associates.

This ultrasonic detector can recognise the high frequency hissing sounds associated with air leaks.

This portable unit consist of a directional microphone, amplifier, and audio filters, and has a visual indicator and earphones to detect the leaks.

It is far more accurate, quicker and cleaner method than applying the soapy water with a paint brush to suspect areas.

The EP542A in just 1-2 hours of use has paid for itself.

For example, if the EP542A detector located a 2.5mm (5 x 0.5mm diameter holes) hole.

It is also ideally used in noisy environments.

To seal/repair the leaks, which most often occur at joints and connections is simple.

Stopping leaks can be as simple as tightening a connection or as complex as replacing faulty equipment such as couplings, fittings, pipe sections, hoses, joints, drains, and traps.

In most cases leaks are caused by bad or improperly applied thread sealant.

It is better to select high quality fittings, disconnects, hose, tubing, and install them properly with appropriate thread sealant.

Non-operating equipment can be another additional source of leaks.

Equipment no longer in use should be isolated with a valve in the distribution system.

Another way to reduce leaks is to lower the demand air pressure of the system.

The lower the pressure differential across an orifice or leak, the lower the rate of flow, so reduced system pressure will result in reduced leakage rates.

Stabilizing the system header pressure at its lowest practical range will minimise the leakage rate for the system.

Once leaks have been repaired, the compressor control system should be re-evaluated to realise the total savings potential.

In the longer term, a good leak prevention program should be put in place and should include the following components: identification (including tagging), tracking, repair, verification, and employee involvement.

All facilities within a plant, using compressed air should establish an rigorous leak seeking program.

A leak seeking prevention program should be part of a overall energy saving program aimed at improving the performance of compressed air systems.

Once the leaks are found and repaired, the complete system should then be re-evaluated.

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