As with diving regulators, rebreathers should be maintained in line with the manufacturer’s recommendations.
There are many components to a rebreather which must be maintained and serviced before returning to diving.
Key parts to consider:
- Servicing of any regulators forming integral parts of the system, such as first and second stages, automatic diluent valves (ADVs), bailout valve (BOV) and manual added valves (MAVs).
- Servicing of the control head, solenoids, and updating computers to the latest firmware.
- Testing and servicing of any cylinders, including O2 cleaning of oxygen cylinders.
- Ensure any components that are user-serviceable (such as hoses, mouthpieces) are maintained following the manufacturers' guidelines, some of which may need to be O2 cleaned.
In the current lockdown, dive shops may not be open as normal, although staff may still be working to offer click and collect sales and carry out equipment servicing. Many servicing facilities are operating reduced working times and may be unable to accommodate a major demand without advance warning.
Where they are operating, a service centre may offer a form of ‘click and collect’ service allowing you to drop off equipment for servicing and arrange collection at a subsequent date. Others are operating only a mailing service, with associated increased cost. In some cases, shops and staff may be receiving grant support to remain closed and so not able to offer servicing at this time.
Sensors, especially oxygen cells, have a limited shelf-life and should be used in accordance with manufacturer instructions and so should be checked for both in-date and accuracy prior to use and replaced in a timely manner (oxygen cells must be replaced in line with the manufacturer's recommendations). Ordering replacements should be done in plenty of time ahead of any planned diving as supplies could be impacted if a sudden increase in demand. Early ordering will ensure you get the resources you require and help suppliers manage stocks to ensure reliable service.
Ensure your absorbent is stored correctly. It should be stored in the original containers and sealed securely. It should be stored within the manufacturers' specified temperature range and should avoid high heat levels or exposure to strong direct sunlight, which can reduce the efficiency and service life. Avoid storing in a garage, shed or other location during the winter that could become subject to freezing conditions as repeated freeze/thaw cycles can degrade the granules.
It is advisable to replace non-rechargeable batteries after a prolonged period of storage. Rechargeable batteries should be fully charged in advance of the next planned usage and checked for deterioration prior to use.
Once any servicing has been completed, fully assemble and test the rebreather unit. It is best to use a checklist, such as that provided by the manufacturer, to ensure that all operation is within specification. Check hoses for any signs of splits, cracks, or other deterioration.
Make sure to test all connections for ease of connection/disconnect, positive/negative checks to demonstrate gas soundness and test the operation of all components. Do not forget the operation of mouthpiece open/closure, BOV, ADV including checks that any isolator (flowstop) operates smoothly and any connections from offboard gases as well.
Conduct system function checks including all alarms, such as those for low PO2. Close attention should be paid to cell function during calibration and tools such as a cell checker may also prove useful.