LDS BS in Nitrox class today...

[MXGratefulDiver]

Is that the only other option? Is it this or "regular service"? How do you know when to replace tires or have your brakes serviced?

"Regular service" is unnecessary if a diver learns to inspect their regulators and identify incipient and minor problems indicating a need for service before the problem seriously impacts performance.

You don't even have to do that much. Almost always there will be early warning signs. A slight "bubbling" in your reg after the inhale (most divers will just instinctively crank up the tension on the second stage spring and forget about it) ... a minor "fizzing" from the first stage (how many of y'all do regular bubble checks?) ... or a noticeable resistance at the beginning of that first breath of the dive. Any of those things MAY be an indication that it's time to get your reg serviced. None of them will cause impending panic or death ... or necessarily even an inconvenience to the diver. But ... like those champagne bubbles that you sometimes will see coming out the join between your HP hose and SPG ... it's an indication that you will want to have it serviced before something more serious goes wrong.

Instructors who preach "regular service" during a nitrox course are using the training time students bought to hawk their business.

I can think of two reasons for this ...

- Instructor training includes an emphasis on selling ... products, services, and continuing education. Depending on the circumstances of their employment, some instructors will take this emphasis to greater lengths than others.

- Liability ... what do you suppose would happen if your instructor DIDN'T tell you about this and someday you had an accident because you neglected to get your regulator serviced. I'd be willing to bet either you or your surviving family members would have a lawyer investigating WHY this instructor didn't follow his training and promote the products, services, and continuing education that his agency told him he should.

... Bob (Grateful Diver)

 

[BerryDiveCenterdotcom]

(I am of the 'dont fix it if it aint broke' mentality and until I have a problem with my regs I dont intend to have them overhauled, plus for what they'll charge for the Regular service plan I could buy a brand new reg every 3-4 years)

That's the mentality to have on your lawn mower or snow blower. Not something that is providing you life support at depths.
This reminds me of people that don't like to leave their cars at a bar after they have been drinking all night. They don't want to pay $30 for a taxi ride home that night. Instead they get a DUI and that ride home now costs you $10,000 court fees/ fines.
My point being if you service your regular annually you could end up saving your self big time aka your life. Servicing your regulator also depends on how you take care of it and how many dives you have on it.
Its better to be safe then sorry, because in our field of fun sorry is too late.

 

[redacted]

My point being if you service your regular annually you could end up saving your self big time aka your life. Servicing your regulator also depends on how you take care of it and how many dives you have on it.
Its better to be safe then sorry, because in our field of fun sorry is too late.

Or you could end up with the service tech who over torques your yoke nut or fails to tighten the hose connection at the 2nd stage. These are the kind of failures that can happen from the occasional service error. And they are also the kind of failures that can result in rapid and total lose of gas. If you really want to be safe rather than sorry, avoid unnecessary regulator service and beware of people who wave the "life support" flag. They are often more concerned with their income than your safety.

 

[Web Monkey]

Now, I'm familiar with CO2 retention and had believed that it was encountered Purely as a result of ineffective/incomplete breathing patterns (ie. breathing too shallow/not fully emptying the lungs)

BUT he also trys to tell me that its related to people who dont service their regs regularly...

A poorly performing regulator can cause increased "work of breathing" which causes an increased CO2 level.

This is also a sneaky back-door cause of panic attacks, when divers don't realize what's happening.

Also, while "lack of service" can cause it, so can "service" if the tech adjusts the reg to breathe too hard.

Terry

 

[halocline]

To the original question: it is not false to state that a poorly serviced reg can cause CO2 retention.

Of course it's false. A reg that breathes so badly as to not deliver enough air for recreational scuba diving is not "in need of service." It's in need of a trash can.

For decades pro divers did extreme dives on regs that by today's standards for performance, deliver very little air with high WOB. How did they ever manage? Why didn't they all pass out from CO2 retention? It's ridiculous to assert that not having your reg serviced annually will cause this sort of thing. Of course, you better listen to the pros at the dive shop, isn't your life worth it?

99% of wear and tear in a reg is manifested by IP creep and leaky 2nd stage seats, neither of which will increase WOB, they'll result in freeflows. Now, a HP seat failure at depth which results in an immediate full on freeflow out all LP hoses, including the inflator, is definitely something worthy of being avoided, but A) that's very rare, and B) it's unlikely to be caused by pushing annual service back.

 

[Web Monkey]

Of course it's false. A reg that breathes so badly as to not deliver enough air for recreational scuba diving is not "in need of service." It's in need of a trash can.

Ever hear of a clogged filter?


Terry

 

[redacted]

Ever hear of a clogged filter?


Terry

I have never heard of one clogged to the point that the regulator was unbreathable. But I'm sure it is at least theoretically possible. It still sounds like such a problem would likely originate in a tank or a hose and is not the type of problem that "annual servicing" could be expected to prevent with any reliability. I suppose it could be accumulation over time but that is just the type of thing that routine inspection by the users can pick up quite easily without having to subject a regulator to unnecessary service.

 

[dave4868]

I'm glad we're discussing the actual mechanics of regulators and the causes of degraded performance or outright failure that might be related to extended maintenance intervals. I was really beginning to wonder if I'd just been lucky to have survived so long using my poorly maintained regulators!

Seriously, I can only speak to my own extended service intervals that I apply to my Sherwood piston 1st stages and basic poppet valve 2nd stages, but even three year, 200-dive DIY service intervals have rarely resulted in any sign of degraded performance.

Even then, the signs were only a slight trickling free flow from elevated IP due to a dry o-ring on the piston head. That happened only once to me in my 14 years with the same regulator.

Frankly, my inlet filter has never needed replacement or been replaced in those same 14 years and 900 dives. I don't see a need to replace it now. Am I being unwise?

I think clogging would be a rare event and very unlikely to be so subtle as to create an unnoticed increased work of breathing (WOB) and risk of CO2 retention. (It hasn't been noticeable even while scalloping at 80' deep, at least not when compared to my simply being out of shape.... )

I really want to know if my approach is substandard, so my questions for anyone with more experience with the servicing of regulators are:

• How many times have you found a significantly clogged inlet filter actually needing replacement? Is there a way to bench test?
• Were those cases of clogging related to extended maintenance intervals or were they related to a more rare set of isolated circumstances, such as gross contamination of a tank or filling station?
• For your own personal regulators, do you routinely replace the inlet filters or do you use them for many years?

I don't quite take the more extreme position of "If it ain't broke, don't fix it", but I'm close to that. I'd probably wait for failure, but don't mostly because I don't want to miss a dive because of gear problems. I believe I can get away with extended maintenance intervals because I think it's pretty easy to tell when a regulator is getting close to being "broke". For some people, more frequent servicing would be better choice.

I've never missed a dive because of regulator problems, I might add.

I'm receptive to getting "smartened up", so feel free to set me straight. I would just ask that you include real personal experience to back it up....

Dave C

 

[Web Monkey]

I have never heard of one clogged to the point that the regulator was unbreathable.

Not unbreathable, but breathing hard at depth (which is what prompted the discussion on CO2 retention).

Terry

 

[halocline]

Even then, the signs were only a slight trickling free flow from elevated IP due to a dry o-ring on the piston head. That happened only once to me in my 14 years with the same regulator.

Kind of a detail, but elevated IP or IP creep on an older sherwood could only be caused by a poor seal at the HP seat, although I suppose if the cup washers were really worn out it could result in slight IP elevation. The piston head o-ring (the big one) separates IP from ambient pressure. If it starts to leak, IP drops, until the first stage opens, repressurizes the IP chamber, and it all repeats. The smaller piston shaft o-ring on this design also separates IP from ambient.

But, overall, I agree with your post that inlet filters rarely get clogged; it's almost always due to serious problems with either the tank or compressor used. I replace filters on my regs when I buy them (I always buy used regs) and inspect them periodically. Occasionally I've found crud in a filter after a charter dive with rental tanks. Not to point fingers, but there is a certain island in the northern caribbean with a central fill station (dive ops often do not own the tanks) that seems to be especially prone to lax tank maintenance. However, no matter how cruddy the filter has occasionally become, it has NEVER resulted in a noticeable increase in WOB in my case.

BTW, this is an excellent reason IMO to avoid the DVT gimmick on some regs. The filter is not visible on those regs and it is impossible to inspect it.