Cylinder Details

Scuba Cylinders

The New Zealand “Guide to Gas Cylinders” specifies that SCUBA Diving Cylinders in normal service must undergo an internal and external visual inspection annually or at any opportune time under twelve months. Some scuba cylinders need more frequent visual inspection, as indicated below.

HEAVY SERVICE. If the cylinder is used in heavy service then it should be inspected every four months. This is defined as:

  • Dropped, fell, was struck, was in an accident, or when the care and maintenance of the cylinder is obviously poor;
  • Was stored improperly and shows signs of damage;
  • Has obvious corrosion since the last visual inspection;
  • Has a gouge, dent, scrape, cut, dig or, in any way, has been damaged since the last visual inspection;
  • Was stored with water, material or matter inside the cylinder;
  • Shows signs of exposure to fire or high heat, including any one or more of the following:
    Charring or blistering of the paint or other protective coating;
    Melting or charring of the metal;
    Distortion of the cylinder and/or any cylinder accessory;
    Melting of fuse plugs, valve hand-wheel, valve protector, and/or any other valve component or cylinder accessory;
  • Has been partially or fully repainted or treated to hide damage and/or fire damage;
  • Is known or suspected to be leaking; or,
  • Is known or suspected of having a crack.

  • As part of the visual inspection the EW is measured using calibrated scales and then the cylinder is filled with water to ensure the actual weight matches the WC stamped on cylinder.

    Dive cylinders must also undergo a Hydrostatic stretch test to five-thirds the service pressure every 2 years. A full visual inspection is carried out at the same time.

    The percentage of permanent expansion under pressure is measured and these figures indicate whether metal fatigue has occurred. If the expansion exceeds 0.01% of cylinder water capacity the cylinder is no longer fit for use. Cylinder testing is conducted in accordance with AS/NZS 2337.1 and the manufacturer’s recommendations.

    On completion of a successful test the test date and our IANZ accredited test station mark is hard stamped onto the cylinder. We also fit a ring of confidence (ROC) with that year's colour.

    Following a visual or hydrostatic test your SCUBA Cylinder will be filled with pure, dry compressed air. Our air is rated to AS/NZS2299.1:2007 and DIN12021. Air quality tests are conducted every 500 running hours so you have the peace of mind that each fill is the best quality you can get.


    Visual inspection and fill: $30.43+GST
    Hydrostatic test and fill: $47.83+GST
    Single fill: $9.57+GST

    9.0 kg LPG Cylinders

    In New Zealand, 9.0kg LPG cylinders must be tested every ten years. It is illegal to fill an LPG cylinder that is past its expiry date.
    The original test date and the manufacturer’s logo is hard stamped onto the neck ring of the cylinder.

    At Tank Test Laboratories 9.0kg LPG cylinders are tested to AS2337.1-2004 and in accordance with “The Guide to Gas Cylinders 2013”.
    Our test stations are fully accredited by IANZ and our expert periodic testers are EPA approved and are audited by IANZ on a regular basis to ensure the highest quality.

    In compliance with “The Guide to Gas Cylinders 2013” the refurbishing process is:

  • At the start of the process the cylinder is completely vented and the old valve is then removed to facilitate the internal inspection.
  • We inspect the external surface of the cylinder for defects, as defined by AS 2337.1-2004. Things we look for are dents, gouges, corrosion, cracks, or any obvious damage.
  • An intrinsically safe light probe is used for the internal inspection of the cylinder. The interior is inspected for rust, scale, corrosion or contamination. Cylinders that fail to meet the standards can be condemned during any of the processes.
  • Valve threads are inspected to see if they are clean, damage free or has any other imperfections that could affect the connection.
  • Purpose built pneumatic tools are used to install the new valve to the correct torque requirements. Old valves are recycled.
  • Every refurbished cylinder is checked for leaks by partially charging the cylinder with compressed air.
  • Once the cylinder passes all of the tests the new test date and our unique test station mark is hard stamped onto an unmarked area of the neck ring. At Tank Test we use a 10 tonne hydraulic tool to clearly mark the tested cylinders.
  • Finally each processed cylinder is issued with a periodic test certificate using approved test station software.

  • At Tank Test we also cater for bulk cylinder refurbishment and our ‘one-of-a-kind’ in New Zealand shot blaster can process 120 x 9.0kg cylinders per hour. Our partially automated refurbishment process allows us to process up to 1,800 and 600 cylinders in Auckland and Christchurch per day respectively.


    Retest 9.0kg cylinder: $24.35+GST
    Refill 9.0kg cylinder: $27.39+GST (Auckland only)
    Bulk 9.0kg refurbishment: POA




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