Twinset service charging components:

• Equipment de-build
• Hydrostatic test x 2 cylinders
• Valve service x 2 cylinders and manifold
• Equipment re-build

In order for a cylinder to be filled with air or Nitrox / Trimix it must have a valid test stamp or sticker.  If this is not present, or it is out of date, then the cylinder will not be filled and must undergo testing. 

Cylinder Test Process: 

• Visual & Hydrostatic Test: The cylinder will be inspected externally - the boot will be removed along with any stickers or labels so that any rusting or damage can be inspected. If there is significant surface corrosion, then the cylinder will need to be cleaned, zinc plated and repainted. 
• Visual & Hydrostatic Test: The valve will then be removed, cleaned and serviced.  Any worn parts will be replaced. If the valve is obsolete (no service kits available) or damaged it will not be reinstalled and you will have the option to replace the valve. 
• Visual & Hydrostatic Test: The cylinder neck thread will be checked with a measuring gauge to ensure it is undamaged and tight. If the cylinder neck thread test fails, then the cylinder will not be returned and will be scrapped due to the risk of catastrophic failure. 
• Visual & Hydrostatic Test: The cylinder will be inspected internally for defects, rust spots etc. If there is slight corrosion, then the internal surface may be cleaned by shot blasting. Major internal corrosion will result in the cylinder being scrapped due to the risk of catastrophic failure. 
• Hydrostatic test only - the cylinder is tested for its ability to return to its normal capacity after being subjected to pressure of 150% of its maximum operating pressure. 
• Oxygen Clean: If the cylinder is to be used for Nitrox/Trimix, then it will go through a cleaning and drying process. O-rings will be replaced with oxygen compatible viton ones 
• Visual & Hydrostatic Test: Reassembly and filling. 

NOTE: Cylinders that fail the hydrostatic test will not be returned and will be destroyed - this is an HSE requirement because they are no longer safe to be filled due to the risk of catastrophic failure.