In-Service Inspection of Pressure Vessels, Air Receivers and Boilers in Victoria

Design registration and in-service inspection are two different duties

If you've read our guide to registrable plant in Victoria, you already know that some pressure vessels, air receivers and boilers need their design registered with WorkSafe Victoria before they're ever installed. That's a one-off check on the design, done by WorkSafe or a registered design verifier.

This article is about a separate, ongoing duty: having that equipment inspected while it's in service. A pressure vessel with a perfectly registered design can still fail — through corrosion, fatigue, a blocked relief valve or a cracked weld — after years of operation. Design registration doesn't catch that. Periodic in-service inspection does.

Plenty of factory owners assume that because their air receiver or boiler was registered and installed correctly years ago, the compliance box is ticked. It isn't. The duty to inspect is continuous, and it sits alongside your broader plant maintenance obligations under our preventive maintenance guide.

Where the duty comes from

The general duty to monitor plant risk sits in Part 3.5 (Plant) of the Occupational Health and Safety Regulations 2017 (Vic). WorkSafe Victoria's own guidance states the obligation plainly: employers must ensure plant is inspected "to the extent necessary to ensure that any risk associated with the use of plant is monitored," and records of inspection and maintenance must be kept for as long as the employer manages or controls that plant.

We could not pin down, from primary legislative text this session, the exact clause number within Part 3.5 that WorkSafe's guidance is paraphrasing (the authorised PDF and AustLII copies of the regulations were not accessible to us at time of writing). If you need the precise regulation number for a compliance file, check the current authorised version of the OHS Regulations 2017 on legislation.vic.gov.au directly, or ask WorkSafe. What's not in doubt is the substance of the duty, which WorkSafe states directly on its own pressure equipment and boiler guidance pages.

Air receivers and pressure vessels: what the inspection regime looks like

WorkSafe Victoria's guidance on air receiver pressure vessels ties inspection frequency to a vessel's pV value — its maximum allowable working pressure (in MPa) multiplied by its internal volume (in litres):

pV value	Inspection regime
Up to around 100 MPa.L	Regular operating surveillance (routine checks, no formal periodic inspection mandated)
Roughly 100–150 MPa.L	Regular operating surveillance
Above roughly 150 MPa.L	External inspection every 2 years; internal inspection every 4 years, with an extended interval option out to 12 years in some circumstances

That inspection schedule is drawn from AS/NZS 3788:2006 (R2017) — Pressure equipment: In-service inspection, which WorkSafe references directly for setting intervals. Pressure relief valves get their own attention: WorkSafe's guidance points specifically to clause 4.6 of AS 3788 for relief valve inspection protocols, since a relief valve that hasn't been tested is arguably a bigger risk than the vessel itself.

Most factory compressed air systems — a receiver feeding pneumatic tools, a paint line, or a packaging cell — will sit above the "surveillance only" threshold once you multiply a typical working pressure by even a modest tank volume. Don't assume your receiver is exempt without doing the pV calculation.

Boilers: a daily-to-yearly layered regime

Boilers, especially unattended ones, get a more layered inspection and maintenance program under WorkSafe's guidance:

• Daily/routine checks — pre-operation checks, water gauge glass blowdown, water-level safety equipment, pressure and water gauge readings, and immediate rectification of any steam leaks.
• Weekly inspections.
• Three-monthly water treatment testing.
• Periodic and yearly maintenance.
• Periodic internal and external inspection by a competent person — WorkSafe's guidance is explicit that unattended boilers should have this carried out on a recurring basis, not as a one-off.

The standards WorkSafe references for boilers are broader than for air receivers alone: AS/NZS 1200:2015 (Pressure equipment), AS 2593-2004 (R2016) — Boilers: Safety management and supervision systems, AS/NZS 3788:2006 (R2017), AS 3873-2001 — Pressure equipment: Operation and maintenance, and AS 4343:2014 — Pressure equipment: Hazard levels.

If your boiler feeds process steam into a confined vessel or you need a person inside it for an internal inspection, that entry is very likely a confined space entry in its own right — see our confined space permit-to-work basics before anyone climbs in.

Who counts as a "competent person"

Both the air receiver guidance and the unattended boiler guidance use the phrase "competent person" for who should carry out these inspections — but in the material we reviewed this session, WorkSafe does not spell out a single, self-contained definition of that term on the pages covering pressure equipment specifically.

In practice, treat "competent" as a documented judgement, not a job title: the person or body doing your internal/external inspections should be able to show relevant training, qualifications and hands-on experience with pressure equipment of the type and hazard level you're operating, and ideally independence from whoever operates the equipment day to day. Most Victorian manufacturers meet this by engaging an accredited third-party pressure equipment inspection body rather than relying on in-house maintenance staff alone — particularly for hazard level A, B or C equipment. If you're unsure whether your current provider meets the bar, ask them directly what accreditation and standard (AS 3788 in particular) their inspection reports are issued against.

Record-keeping: what you actually need to hold

WorkSafe's guidance is specific on this point: you must keep a record of inspection and maintenance for pressure vessels and boilers with a hazard level A, B, C or D as determined by AS 4343:2014, and that record must be retained for as long as you manage or control the plant — not just until the next inspection is due.

A defensible record should show, at minimum:

• The vessel or boiler's identification (registration number where applicable, hazard level, pV value).
• Date and type of inspection (external, internal, or both).
• Who carried it out and on what basis you consider them a competent person.
• Findings, including any defects and what was done about them.
• The standard(s) the inspection was conducted against.
• Next due date for the following inspection.

This is exactly the kind of record a WorkSafe inspector will ask for on a site visit involving pressure equipment — and the kind of gap that turns a routine visit into a notice.

Practical next steps

1. List every pressure vessel, air receiver and boiler on site, with pV value and (where known) AS 4343 hazard level.
2. Confirm the last internal and external inspection date for each, and who did it.
3. Check that whoever inspects your equipment can point to AS/NZS 3788 (and AS 3873 for boilers) as the basis for their inspection regime and intervals.
4. Fix any gap in your inspection records now, before it surfaces during a WorkSafe visit or an incident investigation.
5. Fold pressure equipment inspection dates into the same system you use for other plant maintenance, rather than tracking it separately.

FAQ

Is design registration the same as in-service inspection? No. Design registration with WorkSafe is a one-off check done before certain pressure vessels, boilers and other registrable plant are commissioned. In-service inspection is the ongoing duty to have that same equipment periodically inspected — internally and externally — for as long as it stays in use. See our registrable plant list for the design registration side.

How often does an air receiver need to be inspected? It depends on its pV value (working pressure in MPa multiplied by volume in litres). WorkSafe's guidance, drawing on AS/NZS 3788:2006, sets external inspection at up to every 2 years and internal inspection at up to every 4 years once a vessel is above roughly 150 MPa.L, with lower-pV vessels needing regular operating surveillance rather than a fixed periodic inspection.

Who is allowed to carry out a pressure vessel inspection? WorkSafe's guidance requires inspections to be carried out by a "competent person," without giving a single codified definition in the pages reviewed. In practice this means someone who can demonstrate relevant training, qualifications and experience with pressure equipment — commonly an accredited third-party inspection provider, especially for higher hazard-level equipment.

How long do we have to keep pressure equipment inspection records? For as long as you manage or control the plant. WorkSafe's guidance specifically requires records to be kept for pressure vessels and boilers with a hazard level A, B, C or D under AS 4343:2014 — not just until the next scheduled inspection.

What standard governs boiler inspection specifically? WorkSafe's guidance on unattended boilers references several standards together: AS/NZS 1200:2015, AS 2593-2004 (R2016) for safety management and supervision, AS/NZS 3788:2006 (R2017) for in-service inspection, AS 3873-2001 for operation and maintenance, and AS 4343:2014 for hazard levels. Which ones apply in full depends on your specific boiler and how it's operated.

If you're not confident your pressure equipment inspection regime and records would hold up in front of a WorkSafe inspector, book a site assessment with Ardmor and we'll walk your compressors, air receivers and boilers against the current standard and flag any gaps before they become a notice.

This article is general information for Victorian manufacturers, not legal advice. Last updated: 20 September 2026.