Compressed air leak detection: inspection route and repair verification

Finding a leaking joint is the start of the job. An inspection should produce a register of confirmed defects with repair owners and follow-up checks. This supports a loss-reduction program even when the flow through each leak is not yet known.

The diagram shows 1 preparation, 2 inspection, 3 registration, 4 repair and 5 verification. The return arrow represents regular repeat inspections.

Estimate compressed air leak cost using measured flow and station data.

Prepare the route

Start at the compressor station, then follow the main, branches and consumers. Include fittings, couplings, hoses, air preparation units, valves and drains. Plan access to overhead lines. Normal exhaust from pneumatic equipment must not be registered as a defect.

Record network pressure, process load and operating compressors. Different conditions can change the signal without changing the defect.

Choose a localization method

An ultrasonic detector supports joint-by-joint inspection. An acoustic camera can survey a wider zone; then verify the individual source. Background noise, distance, access and site requirements determine suitability. See leak detection methods.

A suitable soap solution can confirm escaping air at an accessible joint when permitted for the material and process. A vacuum line draws air inward; use the separate vacuum air ingress route.

Register each point

Field	Record
Identifier	Unique tag and register number
Location	Area, line, equipment, reference point and photo
Conditions	Pressure with units and consumer operating mode
Measurement	Instrument, sensor, settings, distance and result
Confirmation	How the source was verified and normal exhaust excluded
Action	Proposed repair, owner and due date
Closure	Repair date and repeat inspection result

A dB value alone does not determine flow in m³/h. A cost estimate needs the instrument's method, measurement conditions, operating hours and the cost of producing air. Do not add readings from different instruments or modes as comparable flow values.

Close the loop

Prioritize defects affecting operation and process requirements, then consider losses and repair access. Isolate and prepare the section under the site's procedure before dismantling a connection.

After repair, revisit the point under comparable conditions. At station level, compare energy use and compressor operation under comparable loads. If energy use does not change, examine compressor control: fixing a leak and proving savings are separate steps.

For an inspection request, provide the network diagram, pressure range, number of production areas, access conditions, operating schedule and report requirements. Contact KEG TRK to discuss the method. LEAKChecker and SDT340 with an appropriate airborne sensor are available for route inspections.

Sources

The DOE compressed air sourcebook covers leak detection and repair programs. Natural Resources Canada discusses compressor control after repairs. The register above is a practical proposal, with no guaranteed savings percentage.