ROUTINE INSPECTION OF A LP-GAS CONTAINER AND FITTINGS
AS 1425 (Australian Standard) indicates that a periodic inspection or routine system check should be carried out at least annually, and at every safety certificate examination for the renewal of vehicle registration, or as otherwise specified by the Authority.
The Standard advise:
- Leakage test. Apply the procedures of AS/NZS 1425:1999 Clauses 6.6 & 6.8.3
- Fuel container life. Check the container date stamp. If it will be more than 10 years before the next periodic inspection, initiate the procedure for inspection and re-stamping in accordance with AS 2337.2
AS/NZS 1425:1999 calls up AS 2337.2 in which the inspection intervals for the container and sub-assembly comprising the vessel, fittings, and associated accessories are defined as being the end of an interval determined from the registered test station mark and associated date stamping.
A registered gas cylinder test station also inspects the sealing threads, surfaces, internal tubes and safety relief devices in the LP-Gas container.
REGISTERED GAS CYLINDER TEST STATION ROLE
In addition to their inspection and assessment role, a registered gas cylinder test station can condemn a cylinder which does not meet the requirements of the Standard. An automotive LP-Gas installer can not condemn an LP-Gas fuel container even though it may appear to have damage or corrosion in excess of the limits described in the standard.
A licensed automotive LP-Gas installer is responsible for an initial inspection and removal of the LPG container to send it to a registered gas cylinder test station should any defects be evident or when the 10 year test is due.
The registered gas cylinder test station inspects and assesses the cylinder to determine whether it should be condemned or stamped for another 10 years of use.
Automotive LPG installers may find that they are called upon to replace faulty container components. ( service valve, automatic fill limiter, or a multi-valve ) in customers vehicles some years before the 10 yearly inspection is due.
Whenever a service valve, automatic fill limiter or a multi-valve is removed from the LPG container, the threads and sealing surfaces of any fittings that have been disturbed should be visually examined for evidence of damage or excessive looseness.
The LPG container should be referred to the registered gas cylinder test station whenever the threads are found to have “excessive looseness” because the threads are required to be gauged using thread gauges complying with AS 2473, and repaired in accordance with the vehicle manufacturer specifications or condemned.
Whenever a new service valve, AFL (Automatic fill limiter) or multi-valve is fitted to an LPG container, new Elastomeric Seals or approved sealing compounds must be used to ensure a leak free joint.
AS 2337.2 requires the gas cylinder test station to remove and replace the safety relief device with one of an equivalent type and performance. It does not provide for inspection of other fittings and accessories on the basis that all other inspections must be carried out by the the vessel installer in accordance with the standard – AS1425 – during commissioning and leak testing.
All external surfaces must be examined for defects and damage.
This may necessitate removal of the vessel from the vehicle, to enable viewing of all external surfaces.
FAULTS OR DEFECTS
All faults / defects must be assessed according to the limits specified. The minimum design thickness is used to establish the limit of a number of defects. Where this thickness is not available, e.g from the specifications, measurements of the actual thickness at an undamaged and non-corroded corresponding area may used instead.
When in doubt refer the LPG container to the registered gas cylinder test station.