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Potential for explosion of aluminium alloy oil/water separators fitted to high pressure air compressors

Issued: 12 April 2005
Last Updated: 12 March 2013


To alert owners and users of high pressure air compressors to a potential safety problem with the older type aluminium alloy air compressor oil/water separator units.


Separator units separate and expel oil from compressed air condensate, subjecting the unit to repeated expansion and contraction forces during the fill cycle. Some air compressors are fitted with older style final stage oil/water separators manufactured from aluminium alloy.

Separator units are designed for a maximum safe cycle life which must not be exceeded. If the safe cycle life is exceeded, catastrophic failure may result. Some manufacturers have recalled aluminium alloy oil/water separator models with a history of failure.

In Queensland there have been explosions involving aluminium alloy Bauer and Mako (three piece mechanical) oil/water separators fitted to breathing air compressors. The explosive forces were of sufficient intensity to have caused serious injuries or death should a person have been in the vicinity at the time of failure.

Action required

Businesses or individuals that operate high pressure breathing air compressor should review the oil/water separator model, type and manufacturer's specifications for safe cycle life.

If the separator is an aluminium alloy unit it should be withdrawn from service until it has been replaced by a suitable substitute or confirmation is obtained from the supplier about the continued safe use of the unit.

Accurate records for compressor operations should be made to determine the oil/water separator's decommissioning point.

Inspection and testing of the pressure equipment is to be carried out by a competent person. This should be in accordance with the manufacturer's instructions, and at intervals not exceeding 12 months.

Further information

Further information about the safe use of high pressure breathing air compressors can be found in section 2.3.6 and 4.2.1 of the Recreational Diving, Recreational technical Diving and Snorkelling Code of Practice 2018 (PDF, 0.61 MB).

Australian Standard AS 3848.2-1999. Filling of portable gas cylinders - Filling of portable cylinders for self-contained underwater breathing apparatus (SCUBA) and non-underwater self-contained breathing apparatus (SCBA) - Safe procedures.

Australian New Zealand Standard AS/NZS 3788 Pressure Equipment – In Service Inspection.