LP Gas regulator over pressure protection

What happened?

A gas system owner has suffered fatal injuries from a gas explosion in their home.

How did it happen?

An LP gas regulator failed to safely control gas pressure supplied to the gas system of a domestic residence. The excessive pressure within the gas system caused the system to leak gas which built up and exploded causing severe burns to the lower body of a person, who has subsequently died from the injuries.

Key Issues

The gas pressure regulator design did not include over-pressure protection (OPP) (see image 1).
OPP is a device or system that prevents gas pressure from exceeding a safe predetermined value.
Initial testing has established the gas pressure at the outlet of the regulator exceeded 150kPa.
Gas appliances are designed and tested to be gas-tight at pressures less than 14kPa.
Excessive pressure (>150kPa) caused valves and joints within the appliance to leak.
Leaking gas built up within the appliance and cabinet beneath the appliance and as ignited by a local ignition source.
The resulting explosion caused fatal injuries to one person, burn injuries to another and significant damage to the appliance (see image 2a) and the property (see image 2b).

Recommendations

LP Gas suppliers should check the first gas pressure regulator on all LP gas installations when filling or exchanging LPG cylinders to ensure the regulator (or additional device) provides over-pressure protection.
Gas work licence holders should check the first gas pressure regulator on all LP gas installations to ensure over-pressure protection complies with relevant safety requirements and commission gas pressure regulators and over-pressure protection devices to ensure safe gas pressures are not exceeded.
Gas system owners should contact a gas work licence holder, or their LP gas supplier, to check safe and correct operation of any LP gas regulator that has been installed for more than 10 years.

Investigations are ongoing and further information may be published as it becomes available. The information in this publication is what is known at the time of writing.

We issue Safety Notices to draw attention to the occurrence of a serious incident, raise awareness of risks, and prompt assessment of your existing controls.

References and further information

Reference within Australian standards that relate to over-pressure protection on LP gas systems include:
AS/NZS1596:2014 The storage and handling of LP gas
- Clause 4.3.1, 5.5.8 and 6.10 with regards to Regulators; and
- Clause 6.10.3 Overpressure protection
AS/NZS5601.1:2013 Gas installations Part 1 General installations
- Clause 5.2.1 Pressure rating of piping and components
- Clause 5.11.12 Over-pressure protection
Petroleum and Gas website: Petroleum and gas safety and health | Business Queensland
Consumer safety website: Gas safety | Emergency services and safety | Queensland Government (www.qld.gov.au)
Current Queensland legislation: In force legislation - Queensland Legislation - Queensland Government

Authorised by Bill Date - Chief Inspector – Petroleum & Gas

Contact: Paul Beaumont, Principal Inspector Gas Work , +61 7 5459 6189 paul.beaumont@rshq.qld.gov.au

Issued by Resources Safety & Health Queensland

Safety: This information is a guide only and is issued to promote safety through experience. It is not to be taken as a statement of law and must not be construed to waive or modify any legal obligation.

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