I've noticed there are a lot of divers who believe because their gear looks clean and still functions, they don’t need to have it serviced. Like dive manufacturers, I beg to differ. As a diver in the Navy we had strict planned maintenance routines to adhere to and for a good reason. We had weekly, six monthly and twelve monthly maintenance routines for our scuba gear which was a necessity considering how much we dived and what we were actually doing underwater. For recreational diving, a twelve monthly service on scuba gear is sufficient for those who dive recreationally and for dives shop hire and student gear every six months is sufficient.
I have been reading through dive shop and technician websites who also advise servicing your gear annually, but I have yet to come across one who goes into detail to explain why. I thought I'd point out a few things which may help you better understand the importance of servicing your gear annually.
A lot of regulators I service look pretty clean visually and do not free flow with air supplied. So this must mean they are in good condition? But more often than not, I will do my pre service function tests and the line pressure and cracking effort will be incorrect and when I dis-assemble the items I find salt, verdigris (green in colour) and/or corrosion. It is not just the first and second stages either. Hoses and gauges are also prone to have a build up of salt, verdigris and/or corrosion, which is often overlooked by dive technicians.
When servicing first and second stage regulators the internal components must be stripped, cleaned, re-assembled replacing various parts, lubricated, precisely tuned and tested to meet manufacture specifications.
Balanced piston first stages have ambient chambers (allows water into an internal chamber within the regulator). This is beneficial to the diver because the supply of air to the diver remains constant irrespective of depth. Whereas an unbalanced piston regulator (does not have the ambient chamber) requires an increased inhalation effort the further you descend, but still provides sufficient air.
Allowing water in the ambient chamber invites salt, sand and any other particles in the water. This is fine however if the ambient chamber is not properly cleaned when rinsing your gear it will remain in the chamber, which over time leads to corrosion and verdigris (especially if the regulator is not used for months on end). This can damage internal components compromising the integrity of the regulator. So whilst the regulator looks clean in appearance, it’s generally not the case for the internal components.
Internal components, which are corroded can reduce in strength and alter in shape. For example a corroded chamber wall which houses a piston and a dynamic o-ring can lose its seal because the corrosion will either damage the o-ring, prevent the o-ring from moving freely, damage the wall of the chamber or all of the above. In short, this will affect the line pressure supplied to the second stage affecting the volume of air supplied to you when inhaling through your regulator.
Another point is corrosion and verdigris in hoses. This is generally a result of water entering the hoses through the second stage regulator. If you do not have your first stage connected to an open cylinder whilst rinsing/soaking your regulators, and you depress the purge button... it allows water to enter the low-pressure hose via your second stage, which remains in there because it is unable to drain back out when you release the purge button. Because the hose is connected to the first stage the water can then enter the low-pressure chamber of the first stage and becomes stuck in there to. Add a bit of salt to this water and you have corrosion and/or verdigris within the hoses connectors and low-pressure chamber of the first stage. This is not optimal considering air travels through these components when we breathe from our regulator.
If a contaminant in air on the surface is is 5%, it will become 20% at 30 meters. So we want to make sure it is free of contaminants. Your dive shop should be testing their air every three months and always display a current air test certificate at their fill station for for you to see (if you don't see, ask to see it). But looking after your regulators is a personal responsibility. Some divers do not care about the condition of their gear and as long as it has no leaks and is not free flowing they will go years without servicing it. Quiet similar to owning a car really, there are those who service their car at the recommended service intervals and those who leave them until something breaks and then get them serviced. You'll often see these people on the side of the highway broken down...
I offer a 12 month warranty on all items I service and I recommend bringing your gear in around the six month mark post service for an inspection which I do free of charge for my customers. I hope these few points give you an idea as to why servicing is important. If you have any questions on your gear please feel free to contact Dive Repairs on (07) 5679 3191.