I just got done (this evening) going through and doing annuals on all my regulators.
This consists of three first stages that are dove regularly, five seconds that are regularly used, and two backup seconds that usually are not used at all, but are around if I need them. One is kept on my boat, the other at the house.
All of the seats were in serviceable condition - I needed to replace none of them (although I have a small supply of those - which are the "problem children" of most regs for getting replacement parts)
The total cost of parts required to service these regulators came to a couple of bucks. Literally. O-rings and O2-compatable grease was it, along with the ultrasonic cleaner, some Simple Green to use in it, some distilled water for a "final rinse", and a few hours of my time.
Now the time, if I was going to pay someone, would have been substantial.
But the parts? Not substantial at all.
Now here's the "screw job" from the "service folks" approach...
Each manufacturer has a "must replace" list. That list TYPICALLY includes all dynamic O-rings, but also typically includes the seats. There is no reason on God's green earth why, if the IP is stable on a first stage, you need to replace the seat. None whatsoever. If you damage it getting it out (for cleaning the retainer, etc) or otherwise have a problem with IP stability then of course it needs replaced - so be careful!
Likewise, if you can tune a second to breathe well on the existing seat, and it is not physically damaged (mild engraving does not count) there is no reason on god's green earth to change THAT one either.
My personal policy is to change ALL O-rings when I have it apart, since they're a whole nickel apiece if that much (in EPDM at that - most manufacturers don't even go to that expense except on high-pressure O-rings), and some manufacturers have done some real brain-fart type things in that area too, like SP's MK20/25 "TIS" bushings that require a 90-duro poly O-ring - one - that is somewhat tough to find in generic replacements. (Use a nice 70 or 80 duro O-ring and you'll find that it leaks over ~3000 psi. Use a viton one and it'll fail over time due to poor wear resistence - VITON should NOT be used in dynamic applications!)
So my usual procedure is to tear everything apart, give any components that are physically dirty a soak in the ultrasonic machine with some simple green solution for a couple of minutes, pull and replace all O-rings with new EPDM ones lightly lubricated with O2-safe grease, inspect all other parts for potential problems and replace as required, reassemble and test.
For firsts, "test" means:
1. First, pressurize it on a "low" tank (typically 300-500 psi), very slowly, to insure that I didn't do something REALLY stupid that would blast high perssure air down the LP ports. Check IP and insure its stable. Breathe off it a few times to check the rebound rate (IP recovery) and make sure it locks up ok at the set IP. If necessary, adjust the IP.
2. Next, pressurize it on a "high" tank (typically either 3000 or 3500 psi, depending on yoke or DIN), again, very slowly (to insure that I didn't do something stupid again), check IP again, then let it sit for an HOUR with the valve turned OFF. The purpose of this is to insure that its not LEAKING anywhere and that the IP REMAINS stable. If the pressure is stable for that length of time, we know its gas-tight and the HP seat is ok.
If ok to this point, reassemble the usual seconds and such and test operation in the pool for a few minutes. If it passes that, its conditionally ok and ready for use (meaning the first actual dive has to happen on a reasonably shallow, non-challenging site)
For seconds, there are more adjustments to be made. For unbalanced seconds getting them to breathe right can be a bit tricky. For balanced seconds its usually pretty easy, except for the bastard children like the SP S600 which has a balance chamber setting that you can't get to without depressurizing the stage (grrrr... now I know why the "cavers" like the G200B and 250HP - they're EASILY settable without having to screw around like that!)
Anyway, once I've verified the cracking pressure I just breathe off the thing and see if it seems to breathe as good as the statistics say it should. Then back on its hose it goes.
Now why the dissertation?
Here's why:
1. You're going to pay for labor irrespective of the "free parts" service deals. Labor to do it RIGHT is approximately what I listed above. I can do seconds in a 15-20 minutes or so each, including setting time; firsts take a bit longer, as there are more bits and pieces to clean and the integrity checks take longer to perform. I guarantee you that NONE of the "paid for" techs will be as extensive in their checks on the first as I am, and few will be as meticulous on the seconds and setting them as I am either.
2. The actual parts that really need to be replaced every annual, most of the time, cost about fifty cents. No, I didn't type that wrong - I said $0.50, and I meant it. The few times you need to actually replace a seat its a few bucks (like $10 or less.) FULL SERVICE KITS can be had on eBAY and elsewhere for $10-15, but I can guarantee you that (1) there's a HUGE markup on these, and that (2) at least half the time the seats that are in the reg are just fine. Not to put too fine a point on it, but I did not have to replace ONE seat this time around across ALL of my regulators!
So, the truth seems to be that (1) you're being juiced BIGTIME on the parts if you're buying them, and for the manufacturer the cost of actual parts is nearly zero, which means the VALUE of what they push in those "warranties" is nearly zero, AND (2) the labor to do it right is expensive, but you're going to pay that irrespective of whether you do it "officially" or not.
Frankly, I think people should learn how to do this stuff - at least on the seconds. The common unbalanced downstream second has about 10 parts in it - TOTAL. I can show anyone how to strip, clean and put one back together in about 20 minutes. If you can manage to screw in a light bulb, you can handle it. If you don't screw around with removing the lever nut (and for most, like the SP R190/380, you don't have to to get the salient components apart and into the cleaner!) you can even avoid replacing the Nylock - not that they're expensive (try the boat store - little SS nylocks are cheap cheap cheap over there.)
The balanced seconds are a bit more complicated simply due to the additional parts count, but even those are not difficult to work on. You might need to be able to change the oil in your lawnmower to handle that job. Essentially all seconds require no special tools to tear down and rebuild, although one "special" tool (an inline adjuster) makes tuning quite a bit easier.
As for firsts, the big deal there is that a mistake can lead to a high pressure leak quite easily, so the "big deal" there is to always check things SLOWLY, and do check your work. But even with those its not a big deal. The issue with firsts is that most require one or two special tools, so you want to standardize on one brand of reg for your diving (and perhaps that of your family) and stick with it, as buying a bunch of different tools gets expensive.
I live by the theory "don't go through life without the information" which includes knowing what goes on behind that purge button.
