How long can a freshly serviced regulator sit.

[pclarke1]

So like many folks on this board I have a few regulators and spares. I am just curious how long a freshly serviced regulator can sit, without being used, prior to it needed to be serviced again? I am asking as I have a couple of spare 1st and 2nd stages that I keep as backups and want to know how often I should cycle them in an out of service. Obviously I would check for free flows and IP creep before using them anyway, but is there a rule of thumb time wise. Mostly I would expect this would relate to the seats taking a set overtime. The annual service "guideline" seems a little excessive, even for gear that is being used.

[antique diver]

I just picked up an Aquamaster from a nice LDS to get it working as a favor for the owner, a long-time friend. A previous employee had serviced it about 30 years ago and appears to have done a good job. Been sitting in the shop since then, and when I put it on a 2000 psi cylinder the IP locked up steady at 125, and no leak from second stage. The duckbill is getting a little sticky, but other than that I think you could take it diving. I'll have a fairly easy job putting this one back in top notch condition for him to take diving. This is an extreme example of course, but obviously not every reg needs an annual overhaul!

[luis]

The first stage valves on all regulators stay open when they are not pressurized. Therefore the seat does not take a set with time. If the first stages has not been contaminated with any salt water, I would not bother servicing them for many years, easily 10 years, but there is no reason they can’t make it for 20 or more years without service.

Again, that assumes they were stored cleaned to avoid corrosion and they are not stored in a hot place. Heat can degrade the O-rings. In a cool dry storage place, O-rings can last a long time.

The second stage seat will engrave with time because the valve is always closed. In the past there has been regulators that offer a “seat saver” to preserve the seat. It is some device to push on the purge button. In some regulators, this can cause more wear on the diaphragm even if it saves the seat. I don't bother with seat savers.

Depending on which type of second stage regulator, in some, the seat will engrave faster than in others. With pneumatically balanced second stages the mechanical spring is very light and the seat will last a relatively long time with minimal engraving.

Second stage in general will need servicing more often, but we are still talking years. Most second stages should still be OK as they approach around 10 years (again, if they were stored clean and in a dry, cool place).

I would base the service interval more on how they are performing (and if they are showing any sign of corrosion or degradation) than just on an arbitrary time period.

Take a look at the inspection check sheet in this thread:
viewtopic.php?f=12&t=3079

[pclarke1]

So just so I am fully clear on what you are saying. Assuming I properly clean my regulator, then I only need to do an "annual service" when I have a performance issue, and for all practical intents an unused rev has no practical shelf life limitations.

[antique diver]

So just so I am fully clear on what you are saying. Assuming I properly clean my regulator, then I only need to do an "annual service" when I have a performance issue, and for all practical intents an unused rev has no practical shelf life limitations.

Probably the first time related limiting factor would be the 2nd stage seat getting deeply indented by sitting on the orifice. This may require just a simple adjustment or maybe even replacement of that soft seat if it begins to leak. Keeping the reg indoors will help prevent summer heat from damaging the rubber parts. The Rip Van Daam reg that I mentioned had always been in an air conditioned environment during its thirty years of hibernation.

[luis]

So just so I am fully clear on what you are saying. Assuming I properly clean my regulator, then I only need to do an "annual service" when I have a performance issue, and for all practical intents an unused rev has no practical shelf life limitations.

In theory that is almost true.

I only say “almost” because (as I mentioned) the O-ring and second stage seat can deteriorate with time. But, if stored in a cool dry place that time can be many years (or even decades for some O-rings).

In practice, the only value of any regular service interval is that many divers are careless and allow salt water contaminants into the regulator. If you are careful and do regular inspection, then there is no real need for any “periodic” service interval (only service as needed).

The yearly service interval is to protect (the regulator and the manufacturer) from the lowest, most careless, denominator (and perhaps to bring customers into their LDS to generate a revenue stream). BTW, several manufacturers are now recommending 2 or 3 years’ service interval.

Standard material degradation of elastomers/ rubber (like aging of O-rings) is somewhat predictable based on good storage conditions, but it takes a relatively long time.

Corrosion due to internal contamination can be unpredictable due to user error. A regulator can be serviced one day and the next day the end user can flood it with salt water, and the regulator needs service again.

It is up to the end user to determine how careful they are and to avoid the need for early service. You don’t have to be too, too careful to extend the life of a regulator, but at the same time if one is careless (or an accident) can result in early need for rebuilt.

Careful inspection (as per the reference above) can often determine if the regulator has been abused or if it is in really good condition. Some fall in the middle and it is hard to determine their condition. Knowing the history of the regulator can help to decide, but IMO, a good inspection is the best tool.

[Ron]

Just for a layman's perspective on what Luis just said, I have a conshelf XIV that I got in the box. It had never been used. It is from 1978, and I've never rebuilt it. I've had it for at least five years, and it is my "go to" single hose regulator. All I do is rinse and soak it in fresh water when I am done diving. My regulator is older than I am by two years


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[dhaas]

While I would always defer to Luis, Bryan, Ron and others who tackle all manner of overhauls my general rules leading salt water trips annually is as follows.

I go by number of trips whether one week in the Caribbean or Pacific trip where close to 50 dives can be done on a trip. After about 4-5 good salt water trips no matter how carefully I rinse / soak my regulator (we're talking single hose here) it's due.

The comment Luis made about a balanced 2nd stage being less pressure on the seat is something I likely was aware of but have forgotten. These days I've been using the El Cheapo' Aqualung Titan which has a balanced 1st stage but unbalanced 2nd stage.

Set up properly it's fine for my needs but the previous Titan LX I and with a balanced 2nd stage did seem to go longer between service intervals. So maybe I'll look around for another Titan LX 2nd stage just for giggles....

YMMV

David Haas
www.haasimages.com

[luis]

Hi Dave,

Well, I have a different opinion on how often to service regulators.

I am not a believer on doing any service that is only based on time interval or number of dives, without some reasoning (or justification) behind it. Preferably, the decision to schedule maintenance is based on some actual observation or other technical, engineering, scientific, or logistics reason behind it.

We are used to changing the oil in our vehicle engines on a regular interval (based on mileage or hours for other engines), but oil breakdown and engine wear is somewhat predictable. Even then, we don’t totally rebuild the engine on a regular interval.

Preventive maintenance and complete rebuilt are two different subjects. I have a hard time thinking of any other equipment were we would do a complete rebuilt on a regular basis.

I am sure you are aware that a very large number of regulator failures occur right after service or when the equipment is new. This is due to what we call “infant mortality” (that is part of the reason we see a year warranty offered on many products). Infant mortality is caused by a number of reasons (new unproven parts working together for the first time, human error, etc).

That is why I am a strong believer on: If it ain’t broke, don’t fix it.
In other words don’t disturb a good working machinery… it doesn’t like it.

I go by number of trips whether one week in the Caribbean or Pacific trip where close to 50 dives can be done on a trip. After about 4-5 good salt water trips no matter how carefully I rinse / soak my regulator (we're talking single hose here) it's due.

David Haas
http://www.haasimages.com

Can I ask you how did you come up to this conclusion? Have you notice actual physical evidence? If you have notice any sign of corrosion, that is a good indicator for service.

I bet your cameras don’t need to be serviced or rebuilt as often… you probably take better care of them…
Just kidding.


Note: I should point out that I am not a reliability or maintainability engineering expert or anything similar. I just have somewhat of a working knowledge of the subject. Terms like Mean time between Failure (MTBF), Objective Quality Evidence (OQE), Infant mortality (as it applies to equipment and machinery), End of Life Failures, “Bathtub curve Failure distribution”, and a few others acronyms, are commonly used in what I do.


The pneumatically balanced second stage has a much lighter mechanical spring. When the regulator is not being used (not pressurized), it is only the spring force holding the soft seat against the volcano orifice. In a conventional downstream demand valve, that spring force is stronger and therefore the seat will normally engrave sooner.

Some regulators are more sensitive than other to the amount of engraving on the LP seat. For example, the Argonaut (DH regulator) second stage can be deeply engraved and still performed just great due to the second stage geometry and the mechanical advantage of the large diaphragm. Most single hose demand valves require more attention.

[dhaas]

Good comments Luis.........

To clarify doing a complete rebuild after every 5-6 salt water trips.

I have noticed the 2nd stage maybe just doesn't seem to give me the easiest "oomph" when pushing an UW camera system around is why. I'm pretty good about drying the dust cap and rinsing but confess to not soaking my regulator for hours even after I get home. Maybe I question how dried salt will really dissolve after 2-3 days of flying home or maybe I'm just lazy

I also have a tech here who's done my Aqualung regs for a few years and does a great job at a low price, too. I probably could learn to do tin my self but again time is always a limited commodity in my world.

Leading trips I have seen exactly what Luis described with failures, free flows or slight leaks right after servicing more often than regulators that have been working fine. So I do tell folks if it isn't broke or showing corrosion they're wasting their money and also setting themselves up to miss dives on their holiday

All good insights!

David Haas
www.haasimages.com

[luis]

I'm pretty good about drying the dust cap and rinsing but confess to not soaking my regulator for hours even after I get home. Maybe I question how dried salt will really dissolve after 2-3 days of flying home or maybe I'm just lazy

David Haas
http://www.haasimages.com

I am not into soaking my regulators for hours either, especially after a couple of days later after flying home. If there was any dried salt left, it will probably dissolve, but any possible corrosion would have already started.

IMO, the best is to rinse the salt water off as soon as possible. If it is possible to rinse it while it is wet, before the salt water dries, you are removing the salt while it is still dissolved. But we know that this is not always possible.

I do a lot of ocean shore diving locally here in Maine. I have a pressure water rinse system that I carry in my vehicle. I have used a 5 gallon water tank with a deck wash-down pump for a few years, but I just bought one of this (I may test the RINSEKIT this weekend)
http://www.rinsekit.com/


When I travel I also rinse (or soak) frequently at the resort and try to do a real good rinse before packing to head back home.

[Bronze06]

I am with Luis on this one. If it is operating well during pre-dive checks (which I conduct the day before the dive period) don't mess with it. Since I am over here in Saudi Arabia and in one of the more remote areas, PMCS (Preventative Maintenance Checks and Services) is a must. I keep a log on all regs I've rebuilt and tested (both in and out of the water). I do not do annual services as per guidance by most regulator manufacturers. This is due to the rather large number of regulators I have acquired (as many of the reg addicts on this site will attest to having as well).
In the log I have an initial service date when I first service or rebuild a reg and then annotate yearly in the log that the reg after checks is either operating to spec, needed an o-ring replace, an adjustment, or needed a full service, etc. With the advent of modern silicon seats and diaphragms this is much less an issue than it was 35-50 years ago with regards to those items. Yes, O-rings, seats and diaphragms will deteriorate in hot dry conditions (I speak from real experience here due to my location), though silicon is much more impervious to the heat, it too can be damaged if not properly RINSED and STORED. Post operations basic maintenance is a must and even rinsing, or soaking in between dives is a plus in this climate.
That said, I have had regs that have sat up for five or more years and after a basic check-out (pool or even a bath tub), they have operated to specifications with no problems. The key is proper rinsing/soaking, light cleaning with soapy water (If needed), thorough drying and a good layering of silicon grease If you are planning to not use the reg for more than a year. The same can be said for all diving equipment (BCs, fins masks, hoses, gauges, etc.) being used. Properly storing in a cool dry and preferably dark place (UV light is hell on all polymers) is a must. Do not store with or near petro-chemicals, or chlorine products as even their vapors will destroy silicon, neoprene and nitrile rubber products RAPIDLY!!.
Bottom line, if you do the correct things as outlined in the above, you can fairly much service every 5-7 years. Pre-checks and Post Operations care and storage are the key. I do not believe that any of the more experienced divers here on the forum would just grab a reg he or she hadn't used for a good while and dive it without a pre-operations check, though some might have been tempted due to said reg appearing to be in great condition. Remember, it is a critical piece of life support equipment and should be treated accordingly.