Air Receiver Tanks Australia

3What Is a Receiver Tank?

A receiver (sometimes spelled “air receiver”) is a steel or composite pressure vessel that sits between the compressor discharge and the plant demand. Its primary role is to stabilise system pressure by accumulating compressed air at high pressure and releasing it incrementally as the plant consumes air. Without it, every small spike in demand (a pneumatic tool firing, a valve opening) would cause the compressor to load and unload rapidly, wasting energy.

The receiver acts as a flywheel for the system: the larger and better matched it is to your duty cycle, the longer the intervals between load-unload cycles, and the less energy the compressor must burn to maintain stable pressure.

Sizes range from 20 L portable tanks (single-user workshops) to 10,000+ L vessels (large factories). Most Australian manufacturing and pharmaceutical plants run 500 to 2,000 L receivers.

5How to Size an Air Receiver

Receiver sizing is driven by three variables:

• Peak air demand: L/s or m³/min.
• Minimum pressure: compressor cut-in, e.g. 6.0 bar.
• Maximum pressure: compressor cut-out, e.g. 7.5 bar.
• Carry time: the measured or required duration of the demand event, in seconds. There is no generic default. Volume scales directly with this term, so a guessed few minutes against a real event of seconds oversizes the vessel by the same multiple.

The formula is:

V = ( Q × t × Pa ) / ( P1 − P2 )

where:
V = receiver volume (litres)
Q = peak plant demand (L/s)
t = the time the receiver must carry the demand on its own, with the compressor unloaded or off (seconds)
Pa = atmospheric pressure (1.01325 bar absolute)
P1 = compressor cut-out (discharge pressure in bar)
P2 = compressor cut-in (inlet air pressure in bar)
(P1 and P2 may be expressed in gauge or absolute; atmospheric pressure cancels in the differential P1 − P2 so the result is identical either way. Ensure that P_atm in the numerator always remains the absolute atmospheric value (1.01325 bar).)

This is the storage (blow-down) method: it sizes the receiver to carry a demand event from stored air alone. If instead you are sizing to limit load/unload cycling on a fixed-speed compressor, use the cycle-frequency method: V = (C × T × Pa) / (4 × (P1 − P2)), where C is compressor capacity (L/s) and T is the full load/unload cycle time (seconds); the factor 4 reflects the worst case at 50 per cent demand.

An example: Your compressor runs 7.5 bar cut-out and 6.0 bar cut-in. Your peak demand is 12 L/s. You want stored air to carry that peak for 10 minutes (600 seconds) with the compressor unloaded.

V = ( 12 × 600 × 1.01325 ) / ( 7.5 − 6.0 )
V = ( 7,295.4 ) / ( 1.5 )
V = 4,864 litres

In this case you would specify a 5,000 L receiver to give comfortable margin and account for real-world inefficiencies (compressor unload delay, condensate drain lag, minor leaks).

Rule of thumb: as a rough first pass, allow about 3 to 5 litres of receiver per L/s of compressor FAD for a VSD machine, and about 10 to 15 litres per L/s for fixed-speed load/unload control (the figure quoted at the top of this section). Treat that only as a sanity-check starting point. The receiver you actually need is set by the storage formula below, because it depends on your peak demand, the pressure window you can tolerate, and how often you are willing to let the compressor cycle. Where those are known, size from the formula, not the rule of thumb: V = (Q × t × Pa) / (P1 − P2). Our air receiver tank sizing guide works that formula through a full SI worked example and reconciles it against the cycle-frequency method.

Indicative sizing reference table

The table below sets the rule-of-thumb against typical compressor outputs as a first-pass sanity check (a 45 kW rotary screw delivers roughly 120 to 130 L/s FAD at 7 bar gauge). They are indicative only. Size from the storage formula above against your own peak demand, pressure window and acceptable cycle frequency before you buy.

Those bands look at compressor output. They do not look at pulsation. If you are sizing for one of the piston compressors, the receiver has a second job to do: a reciprocating machine pulses hard at every stroke, and it takes receiver volume of roughly 6 to 10 times the swept volume per stroke to damp that out. Run the storage formula, work out the pulsation figure as well, and buy the larger of the two. A rotary screw pulsates far less, which is why the bands above hold up better against a screw than against a piston.

Before you lock the size in, remember the formula only sees the demand you feed it. If a chunk of that demand is leaks, the leak cost calculator shows what they are costing you, a compressed air leak detection survey finds them, and an independent compressed air audit replaces estimated peaks with measured ones.

Sized it? Now check whether it needs registering

Depending on its pressure and volume, that receiver may also need registering with your state regulator before it goes into service. In New South Wales that duty runs through SafeWork NSW, and the detail sits in our guide to pressure vessel registration in NSW. That receiver may also need registering. Get the worksheet near the top of this page: a free two-page PDF that runs the AS 4343 hazard level calculation in five lines and gives you the registration checklist for your state or territory.

7Australian Standards and Compliance

Air receiver tanks in Australia are designed, manufactured, and inspected under several overlapping standards:

AS 1210:2010 Unfired Pressure Vessels (Design and Manufacture)

This is the design standard for pressure vessels in Australia. It covers wall thickness, welding quality, hydrostatic testing, and material selection. Any receiver sold in Australia must be certified to AS 1210 or equivalent; vessels built to earlier editions such as AS 1210-1997 remain compliant in service.

Key requirements:

• Certification plate must be permanently fixed to the vessel.
• Hydraulic test pressure must be clearly marked.
• Manufacturer identity and manufacturing date must be visible.
• Minimum wall thickness varies by pressure and diameter; calculated thickness must be stamped on the vessel.

AS/NZS 3788:2024 Amd 1:2025 (In-service inspection of pressure equipment)

This standard covers in-service inspection, maintenance, and periodic testing of pressure equipment in operation. Duty-holder obligations under the state and territory WHS regulations (which follow the Safe Work Australia model WHS framework) require pressure equipment to be inspected on the schedule set in this standard.

Key in-service requirements:

• External visual inspection: AS/NZS 3788:2024 Table 4.1 Item 6 bands compressed-air vessels by the pV product (design pressure in MPa multiplied by volume in litres), not by AS 4343 hazard level: above pV 150 MPa·L the external interval is 2-yearly; at or below that, the cadence is set by a competent person under Table 4.1 Note 6. Look for corrosion, dents, leaks, and condition of safety devices. Hazard level still matters for registration: under AS 4343:2014 the hazard level value for a non-harmful gas is H = 10 × P × V (Equation 2.1), so a typical 200 to 1,000 L receiver at 800 kPa design works out at hazard level C, not Level A or B.
• Internal inspection: For compressed-air receivers above pV 150 MPa·L, AS/NZS 3788:2024 Amd 1:2025 Table 4.1 Item 6 requires internal inspection at 4-year intervals (external inspection at 2-year intervals), with a 12-year extended interval available under the standard’s conditions. At or below pV 150 MPa·L, intervals are set under Table 4.1 Note 6 at the competent person’s discretion. Internal inspection is not waived outright for larger receivers; dry, well-drained air carries lower internal-corrosion risk, but confirm the interval for your vessel with the competent person.
• External inspection (additional, above pV > 150 MPa·L): 2-yearly per AS/NZS 3788:2024 Table 4.1 Item 6 for compressed-air receivers where pV exceeds 150 MPa·L. Below pV 150 MPa·L, external inspection cadence is set by a competent person; at or below pV 100 MPa·L no commissioning or first in-service inspection is required by Item 6.
• Hydrostatic testing: AS/NZS 3788:2024 Table 4.1 sets no routine hydrostatic re-test interval for in-service air receivers. A hydrostatic test is carried out when a competent person calls for one, most commonly to verify a repair or alteration (Section 6 and Appendix A.8.5 of the standard).
• Relief valve test: At each internal inspection and after any maintenance.

A compliant receiver must have:

• A calibrated safety relief valve (set slightly above operating pressure, typically 0.5 bar above cut-out).
• An isolation ball valve or equivalent (so the vessel can be de-pressurised for maintenance).
• A drain valve or auto-drain trap at the sump.
• A pressure gauge (mechanical, not digital only, for safety-critical applications).
• Labelling showing design pressure, test pressure, maximum operating temperature, and date of last internal inspection.

Safe Work Australia Model WHS Framework

State and territory WHS regulations, which follow the Safe Work Australia model WHS framework, require the duty holder (site owner or plant manager) to:

• Equipment register: keep a register of all pressure equipment on site.
• Inspection scheduling: schedule and record all inspections and tests.
• Competent-person inspection: engage a competent person (as defined by the relevant WHS/OHS regulation; a licensed Pressure Equipment Certifier or AICIP-credentialed inspector is one example) to carry out or witness in-service inspections and record the outcome.
• Design-limit operation: ensure no receiver is operated beyond its design pressure or temperature.

Inspection intervals and competency for in-service air receivers are set by the relevant jurisdiction’s enacted WHS or OHS law and regulator guidance. AS/NZS 3788:2024 (incorporating Amendment 1:2025) is the technical inspection reference standard, but it is not itself the legal source. WorkSafe Victoria’s air-receiver guidance is one example of a regulator that requires inspection by a competent person and record retention for hazard-level A to D vessels; it does not frame a single five-year Pressure Equipment Certifier certificate as the universal Australia-wide proof of compliance. Operators should check the specific inspection interval and competency requirement against their own jurisdiction’s regulator.

9Inspection and Maintenance

Once commissioned, the receiver is governed by the AS/NZS 3788:2024 Amd 1:2025 inspection schedule. Our guide to air receiver inspection requirements covers the pV bands, the external and internal intervals, and who may carry them out.

Annual External Walk-Around (duty-holder good practice)

A 12-month external walk-around is conservative duty-holder practice aligned with state and territory regulator guidance. It is not an AS/NZS 3788:2024 Table 4.1 interval: for compressed-air vessels, Item 6 sets the external cadence by pV band, as covered above.

• Walk around the vessel and check for visible corrosion, surface cracks, dents, or deformation.
• Confirm the safety relief valve is free of debris and the discharge tube is not blocked.
• Check that all bolts and anchors are tight.
• Verify the pressure gauge needle moves smoothly and reads within ±2.5% of the true system pressure (compare with a calibrated test gauge).
• Confirm the isolation valve operates smoothly (does not jam or leak).
• Activate the manual drain or auto-drain and inspect the condensate quality (colour, odour, presence of oil).
• Record the date, findings, and signature of the inspector in your compliance register. If defects are found, report them to the site manager and compressor service provider.

Hydrostatic Re-Testing (when it actually applies)

AS/NZS 3788:2024 Table 4.1 sets no routine hydrostatic re-test interval for air receivers, whatever their age. Australian vessels are designed to AS 1210 (the current edition is AS 1210:2010; vessels built to earlier editions such as AS 1210-1997 remain compliant in service), and in-service hydrostatic testing is not a calendar cycle under either standard. A hydrostatic test is called for by a competent person where it is needed, most commonly to verify a repair or alteration under Section 6 of AS/NZS 3788:2024, with the test procedure in Appendix A.8.5. Check your certification plate and inspection records rather than assuming a 10 or 15 year cycle.

An air receiver above the AS 4343 registrable threshold must have its design registered before use, and the rules differ by state (see our Australian pressure vessel registration guide for the state-by-state picture). See for example the Victorian pressure vessel registration guide, where design registration applies but item registration does not.