Jan 2018

Papakura LPG Bottle Swap Filling Plant; Safety Case Summary

The Safety Case Concept

OnGas have constructed a Liquid Petroleum Gas (LPG) bottle swap processing facility at 37 Hunua Road in Papakura. The plant has the capacity to fill six hundred standard 9 kg LPG bottles per hour, and is the first semi-automated LPG filling plant to be constructed in New Zealand.

Trucks bring in empty bottles, and leave with full ones. LPG is stored onsite in two 50 tonne bulk storage tanks.

The plant is defined as a Major Hazard Facility under the Health and Safety at Work (Major Hazard Facilities) Regulations 2016. As such, it is required to have a Safety Case (which is a report to prove how and why the plant is safe to operate). WorkSafe must accept the Safety Case before a plant is permitted to operate. The Papakura Bottle Swap Safety Case was accepted by WorkSafe on 9th October 2017.

What are the hazards associated with the bottle swap plant?

By far the most important hazard to manage is the loss of containment of LPG. LPG is extremely flammable and may ignite, or in some cases explode, if released to atmosphere. What happens when LPG is released depends on the quantity released, the direction and strength of the wind and what sources of ignition can be reached by the gas.

What is being done to control the risk of a loss of containment?

The plant has a range of automatic or in-built safety systems including: gas detection and shutdown systems, breakaway couplings (which close if a truck drives away while unloading LPG), and timers which prevents overfill of an LPG tank if the driver is incapacitated.

A fire water system, including a spray cage for LPG truck unloading and hydrants is designed to quickly reduce the risk from a fire.

There are collision barriers and speed limits to reduce the likelihood of incidents caused a by a truck impact, and entry controls to prevent unauthorised vehicles getting into the plant.

As well as all this, the plant/building design, construction, staff training, equipment inspection and maintenance regimes all must meet strict criteria.

What will happen should an emergency occur?

Although the risk of harm to the public from operations at the facility is extremely low, it is not zero.

A comprehensive Emergency Response Plan (ERP) has been prepared to minimise the risk of harm should multiple controls fail. This plan was reviewed and approved by Fire & Emergency NZ and Civil Defence Emergency Management.

The ERP is regularly tested to ensure efficient and effective response. Every Wednesday at 9:30 am the evacuation alarms are tested together with a “voice over” which explains the purpose of each alarm. The “on-site” fire alarm and general evacuation alarm will barely be audible from the street. The “off-site” evacuation alarm is a variable two-tone (hee-haw with sudden transition) siren. It is designed to be audible at potentially affected neighbouring properties.

If you hear this alarm (and it is not 9:30 am on a Wednesday), anyone within 400 m from the facility needs to evacuate to one of the muster points shown on the satellite photo below. The siren automatically calls Fire & Emergency NZ and is manually operated by OnGas staff. They will be in position to guide you to one of the muster points (A, B, C or D) in the unlikely event that this is required.

OnGas LPG Bottle Swap Plant 37 Hunua Road
Emergency Muster Points

If you hear the two-tone (hee haw) emergency siren and you are inside the green circle – evacuate to muster point A, B, C or D.

OnGas evacuation green circle Legend for evacuation point Legend for assembly point

Once the emergency is over an “All-Clear” signal will sound. This is a continuous (single note) siren.

Need more information?

If you need more information about the OnGas Papakura BottleSwap plant or the WorkSafe approved safety case, please contact the Plant Manager, Philip Thompson at Philip.Thompson@Vector.co.nz or call 09-213-0279.

End of article

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