Regs, to service or not to service

[halocline]

@BurhanMuntasser nothing against them, just against packing grease into the chambers and not opening them up for extended periods of time. The damage isn't imagined, it's been witnessed and independently brought up on this very thread... It is real, it does happen, and yes, it can happen on diaphragms, but is not likely.

My only real aversion to pistons is when people start talking about how they're better than diaphragms because they flow more air. While this is true, the diaphragms are still limited by the valve in terms of how much air they can actually deliver to a diver, so this point is moot.

Two comments:

1. Packing the ambient chamber of piston regs for environmental seal is a decades-old practice, that when done correctly, is very effective. It is true that if the person doing the service does a poor job and leaves voids, water can get in and cause corrosion. I've seen this, in fact I just cleaned up a MK10 and replaced the piston because the person who had packed it before I bought it did a poor job. But it's not rocket science, and I've seen packed piston regs that were immaculate after several years of use without service. And there are plenty of ways for bad techs to screw up diaphragm regs.

2. The air flow argument is a bit silly, because both piston and diaphragm 1st stages can flow WAY more air than the tank valve or any 2nd stage can. As an example, the MK25 claims a flow rate of 300 SCFM. That rate would theoretically empty an AL80 in about 15 seconds. 1st stage flow rates are usually measured out all the LP ports at once with a constant high flow HP air source. IP drop and recovery under demand is a much better indicator of 1st stage performance.

The old piston vs diaphragm argument has been going on for decades. Clearly they both work extremely well, or one of the two designs would have dominated the market.

 

[KeithG]

1. Packing the ambient chamber of piston regs for environmental seal is a decades-old practice, that when done correctly, is very effective.

This does not work so well if you have a Sherwood first stage with a dry bleed system. Okay, it does work, but it tends to totally screw up the dry bleed. Guess my LDS tech did not think it through enough before they decided to free style on my gear...

 

[halocline]

This does not work so well if you have a Sherwood first stage with a dry bleed system. Okay, it does work, but it tends to totally screw up the dry bleed. Guess my LDS tech did not think it through enough before they decided to free style on my gear...

Sounds like your LDS tech likes the LSD method of regulator service.

 

[Kharon]

It's been a few years, but I suspect using LSD to service regulators might not be the best approach.

Not sure. You would certainly get a totally focused (though probably totally confused) view of the reg. Might take several days to get the service done. After all, you would have to comtemplate the all of the reg in every variation. Oooommmm - lol.

 

[TMHeimer]

as someone who also services my own reed instruments, are you saying you're OK disassembling the keywork on a clarinet, but not a regulator? or just taking the 5 pieces apart to put in the case?

Yeah, I take the screws out if some simple work (like pad replacement, but not much more), then put the screws back in. 19 years teaching Band gave me such in depth experience. I've only seen a reg apart once or twice. When I used to DM I was always SURE we had backup regs and the usual other spare stuff for the classes.

 

[tbone1004]

Yeah, I take the screws out if some simple work (like pad replacement, but not much more), then put the screws back in. 19 years teaching Band gave me such in depth experience. I've only seen a reg apart once or twice. When I used to DM I was always SURE we had backup regs and the usual other spare stuff for the classes.

fair enough, though clarinets are a helluva lot simpler than saxophones. Repairing a regulator is infinitely easier than getting the octave mechanism or G# mechanism put back together and adjusted on a saxophone

 

[halocline]

My 4 regulator sets I use on every dive get full rebuilds annually. But these regs are used at 110 feet for 90 minutes 1400 feet back in a cave. So my priorities are a little different then your average recreational diver.
Also I have a set of regs that are for salt water only and will never see a cave.
To each their own, it's your choice.

My dedicated cave set received a full rebuild including all port plug and hose o-rings shortly before I took intro. These are old regulators, BTW, that I had used for several years, I couldn't remember the previous service on some of the stages, so I just wanted to establish a time frame for the whole set that would be easy to remember. Now, I just inspect before each trip and I'll wait for some indication that they need service. Personally, I think that's more reliable than pulling them apart every year. I certainly understand the difference in mind set when you're using your regs in a cave, but logically, over-servicing is likely to produce a problem. Well designed, well maintained (fresh water soaking) regulators can go a very long time with almost no wear and tear. And ironically, the cave environment is probably the easiest on regulators; it's clean fresh water, no UV light, no knocking around on a boat, no dirty rinse tanks, and usually gas from a reliable source.

 

[Macan]

I teach Tec and Rec and own several regulators for my student's use during their training. I standardize on Apeks regs and have no regrets in terms of reliability and performance.

I have no issues servicing Apeks US4, DS4 first stages and ATX50, AT20, XTX 200 and XTX 50 second stages.

However, when it comes to servicing the Apeks FSR first stage, I'm stuck. The FSR requires a special Apeks tool to remove and install the HP Valve Seat. Is there a workaround solution without having the Apeks special HP Seat Tool?

 

[KeithG]

Is there a workaround solution without having the Apeks special HP Seat Tool?

Make your own tool?

Over the years my tool box has collected lots of odd specialty tools. Some of them were purchased for one time only jobs (cost of the tool was much less than taking something to a real repair shop). Many of the tools I custom fabricated from other tools and bits.

My favourite is a 1 inch long 1/2 inch open end spanner required to remove the carburetors from my old English sportscar.

 

[halocline]

My 4 regulator sets I use on every dive get full rebuilds annually. But these regs are used at 110 feet for 90 minutes 1400 feet back in a cave. So my priorities are a little different then your average recreational diver.

I wanted to think a bit about the logic behind this and my approach, which is wait for some indication. The way I see it, there are only a few possible causes for a regulator to have problems:
1. A part could wear out and fail, like an old o-ring or seat.
2. A part could fail before it is worn out, due to some random defect.
3. A repair technician could make a mistake while working on the reg which causes a problem.
4. Something in the environment while diving causes a problem, or in the air supply.
5. A problem could happen due to abuse or poor treatment by the diver

Okay, so annual service definitely addresses the first reason. No part is going to wear out in less than a year unless the reg is truly used very heavily, like maybe 200 dives/year or more. But, IME parts in scuba regulators tend to last a very long time before showing significant wear. I have seen regulators go without service for several years, even a decade and still show no evident signs of wear, except maybe imprinting on the 2nd stage seat.

The 2nd and 3rd reason for failure are actually at increased risk by annual service. Parts that are known to not be defective are replaced by parts that are not proven. And the possibility of mistakes by a technician are, of course, increased with the frequency of work.

The 4th and 5th reason are not affected by annual service, except in terms of accelerated wear due to abuse. This would be a legitimate reason for annually servicing regulators.

Overall, I am convinced that annual service actually increases the likelihood of failure for most divers, as opposed to regular inspection and service when indicated, given moderate use and proper care by the diver.