Annual TPR Valve Test (AS/NZS 3500) SWMS

Temperature and pressure relief valve testing covers the periodic testing and replacement of the temperature and pressure relief valves fitted to hot water systems — the safety valves that relieve excess pressure and temperature to prevent a hot water tank from over-pressurising or overheating. The relief valve is a critical safety device, and a valve that has seized, corroded or failed can allow a tank to over-pressurise, with the risk of rupture or steam release, so the valve is tested and replaced at the required interval. This document is written on the basis that relief valve testing is carried out by a licensed plumber, with the valve operation verified or the valve replaced and the relief discharge confirmed safe.

Temperature and pressure relief valves on hot water systems are maintained in connection with AS/NZS 3500.4, the heated water services part of the plumbing and drainage standard, under which the relief valve and the safe disposal of relief discharge are required. The valve is tested by operating it to confirm it relieves and reseats, or replaced at the required interval, because a seized or failed valve cannot protect the tank. This document coordinates the valve-testing, replacement, discharge and scalding controls so the relief valve continues to protect the hot water system.

Hazards identified

9 hazards covered, sorted by priority.

Control measures

Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.

1. 1Administrative: test the temperature and pressure relief valve by operating it to confirm it relieves and reseats, or replace it at the required interval, so the valve can protect the tank.
2. 2Engineering: where the valve is seized, corroded or failed, replace it with a correctly rated valve so it protects the hot water system to AS/NZS 3500.4.
3. 3Engineering: manage the hot water and steam release during testing, controlling the discharge so it does not scald, and confirm the relief discharge is piped to a safe, visible disposal point.
4. 4Engineering: manage the stored energy and pressure of the hot water system, isolating and controlling hot water before working on the valve.
5. 5Administrative: confirm the valve rating is correct for the system, and reinstate the valve and discharge correctly after testing.
6. 6Administrative: record the test or replacement and schedule the next test at the required interval, and verify the valve and discharge perform before completion.
7. 7PPE: gloves and protection against hot water and steam when operating the valve, in addition to the standard PPE.
8. 8Administrative: ensure the work is carried out and certified by an appropriately licensed plumber under the relevant state or territory plumbing licensing scheme, with the backflow, testing or other endorsement required and a compliance or test certificate issued where required.
9. 9Administrative: all workers must hold a valid White Card (General Construction Induction Training, CPCCWHS1001) where the work is construction work, with the plumbing competencies and any backflow, confined space or testing endorsements required for the work.
10. 10Administrative: conduct a pre-start toolbox talk covering the day's work, identified hazards, isolations, required PPE and emergency procedures, and record attendance in the consultation section.
11. 11Administrative: consult workers and any health and safety representatives on the work and its risks, record the consultation, and keep this document available at the workplace.
12. 12PPE: eye protection to AS/NZS 1337.1, hearing protection where required, gloves appropriate to the task, and Class I or Class II safety footwear with protective toecap to AS/NZS 2210.3.
13. 13Administrative: review and update this SWMS whenever the work scope changes, after any incident or near miss, when a worker or health and safety representative raises a concern, when new hazards are identified, or at minimum every 12 months.

Applicable Codes of Practice

Worked example

A licensed plumber is engaged to test the temperature and pressure relief valves on the hot water systems at a property. Each valve is tested by operating it to confirm it relieves and reseats, with the hot water and steam release during testing managed and the discharge controlled so it does not scald. Where a valve is seized, corroded or failed, it is replaced with a correctly rated valve so it protects the hot water system to AS/NZS 3500.4. The relief discharge is confirmed piped to a safe, visible disposal point. The stored energy and pressure of the system are managed, isolating and controlling hot water before working on the valve, and the plumber wears gloves and protection against hot water and steam. The valve rating is confirmed correct, and the valve and discharge reinstated correctly after testing. The test or replacement is recorded and the next test scheduled, with the valve and discharge confirmed to perform before completion. The records are retained.

Related legislation

• Model Work Health and Safety Act — primary duty of care; the duty to consult workers; the reckless-conduct offence; and notifiable-incident provisions, as enacted in each jurisdiction.
• Model Work Health and Safety Regulations — Section 291 high risk construction work and the SWMS preparation and review duties, and the confined space provisions where applicable, as enacted in each jurisdiction.
• The relevant plumbing and drainage standards AS/NZS 3500 (Parts 0–5), AS/NZS 1547 for on-site wastewater, the AS 4032 and AS 1357 valve standards, AS/NZS 2845.3 for backflow field testing, and AS 1851 for fire-system service, are called up by the state and territory plumbing and building safety legislation, together with the requirements of the relevant network utility.
• Plumbing work is licensed under each state and territory's plumbing licensing scheme, with backflow and testing accreditation required for that work, and compliance or test certification required for notifiable work; electrical work is carried out by a licensed electrician.
• Victoria operates under the Occupational Health and Safety Act 2004 and the Occupational Health and Safety Regulations 2017, with the high risk construction work and confined space provisions applying in place of the model instruments.

Frequently asked questions