Under the Occupational Health and Safety Act 2004, employers must, so far as is reasonably practicable, provide and maintain a working environment that is safe and without risks to the health of employees and independent contractors. Where the risk cannot be eliminated, it must be reduced so far as is reasonably practicable.
Employers must provide employees with the necessary information, instruction, training or supervision to enable them to do their work in a way that is safe and without risks to health.
Further, employers must, so far as is reasonably practicable, eliminate or reduce any risks associated with plant.
Under the Occupational Health and Safety Regulations 2017, an employer must ensure that plant is inspected to the extent necessary to ensure that any risk associated with the use of plant is monitored. An employer must also keep a record of any inspection and maintenance carried out on certain categories of plant for a period that the employer has management or control of the plant.
Inadequate inspection and maintenance of air receiver pressure vessels.
Inspection and maintenance often focuses solely on the compressor. The air receiver does not have moving parts and is not given the priority it requires.
Figure 1 The poor external condition of this air receiver showing a build-up of rust, oil and dust, signals a need for improved operational surveillance, inspection and maintenance.
Pressure vessels can fail and explode, causing injury and death. The Longford gas explosion in Victoria was the result of pressure vessel failure after a heat exchanger in the gas refining process exploded.
You must, so far as is reasonably practicable, eliminate or reduce any risk associated with plant.
An air receiver is a type of pressure vessel. It is a tank that stores compressed air for large demands in excess of compressor capacity.
It is important to keep the air receiver in a safe working condition. Ensure inspections are done by a competent person in line with the following inspection intervals table.
You must keep a record of any inspection and maintenance carried out on pressure vessels with a hazard level A, B, C or D as determined by AS 4343 Pressure equipment.
Inspections should be carried out by competent person(s) at intervals to keep the air receiver in a safe condition.
Inspection intervals sourced from AS/NZS 3788:2006 Pressure equipment—In-service inspection.
Note: pV is determined by multiplying pressure (MPa) x volume (Litres).
|Pressure equipment||Commissioning inspection required||First yearly inspection required||External inspection||Internal inspection||Typical interval for overhaul and bench test|
pV less than or equal to 100MPa.L
|No||No||regular operating surveillance||n/a||n/a|
pV greater than 100MPa.L
|Yes||No||2 yearly||4 yearly||n/a|
|Pressure relief valve||Yes||Yes||yearly||n/a||5 years|
Figure 2 Inspection reminder sticker gives a quick visual reference on the status of the inspection program. This does not substitute for inspection records.
Ensure that the pressure relief valve is overhauled and bench tested by competent persons at intervals to keep it in a safe condition.
Operational surveillance and monitoring of the pressure relief valve, blowdown valve and pressure gauges should be built into standard operating procedures.
Monitor, inspect and maintain according to the manufacturer or supplier’s recommendations, all components of the compressed air system, such as the air receiver, air compressor, air lines/hoses and fittings.
Only use the grade of compressor oil recommended by the manufacturer.