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April 2005 Vol. 31, No. 4   RSS Feed for Undercurrent Issues
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Regulator Servicing

— what should you expect when it’s time for service?

from the April, 2005 issue of Undercurrent   Subscribe Now

What can you expect when you get your regulator serviced? That depends. If you walk into your local dive store and proclaim that your trusty regulator is free flowing, the technician’s response will be to disassemble your regulator, clean it, and reassemble it, replacing the filter and all the soft parts (o-rings and seats). These are the parts that typically come in an annual service kit. If instead you report that your regulator is stuttering and honking, the technician’s response will be the same. If the complaint is “my regulator is breathing wet,” ditto. No matter what the problem, the response is almost universally the same.

And there is some logic to this — performing these steps will generally fix the problem... and truthfully, it is time-savvy. Rather than spending his time and your time and money diagnosing the problem, he simply fixes everything. An annual service or overhaul can run anywhere from $40 to $110 for the labor plus parts. Most regulator warranties will cover the cost of parts, which may lift $20 to $40 from your wallet if your regulator is not covered.

If your regulator is not misbehaving and you don’t believe it needs an annual service, but you would feel better about your upcoming dive trip if you had it checked out before leaving, most operations will do a bench check or inspection for a lot less money (some stores will even do it free). However, ask what the terms “bench check” and “inspection” mean to the technician. To a trained technician who works in a well-equipped service center, a “bench check” means that the regulator is hooked up to a diagnostic machine called a flow bench. By pushing buttons and twisting valves, the technician can check the interstage sure, cracking pressure (inhalation effort) at the second stage, exhalation effort at the second stage, and flow rate through the regulator. He can watch real gauges and give real numbers, and he can do all of the above at different tank pressures. He may or may not perform the same service when an “inspection” is performed.

Perhaps no more than one dive shop in 10 has a full flow bench set up, which runs up to $4000. However, a mechanically adept scuba service technician can rebuild and tune a regulator with only a high pressure gauge and an interstage pressure gauge. And he can get close to the correct numbers. He just can’t nail it as well as service technician with a flow bench.

Checking It Out

By way of comparison, we took a Sea Quest regulator along with an Air II and attached gauges to a local dive operator, Harbor Dive Center, Sausalito, CA, and asked them to perform a bench check on the rig. (Note that while the term “bench check” was used, there was no actual flow bench involved.) We watched as retired owner cum technician Jack Kuhn measured the intermediate pressure from the first stage to be sure it was within manufacturer specs (generally about 130 psi). This level allows the regulator to breathe easily without free flowing. It’s also below the pressure necessary to burst the low pressure hose (250 to 300 psi).

Next, Kuhn repeatedly pressed the second stage purge button, measuring how quickly the air flow rebounded from a purge (or breath) to a consistent “lock pressure.” A slow rebound or a tendency for the interstage pressure to creep up past the lock pressure would indicate a need for full service.

Next, he checked the filter for salt or corrosion, which he said is a clue to conditions inside the first stage as well. Then he checked the low pressure valve seat components. Finally, both stages and all hoses were submerged to double check for leaks, especially in the high pressure swivel of the submersible pressure gauge.

Harbor Dive Center charged $15 to conduct these tests and make necessary adjustments to the regulator (the Air II didn’t require any service). They replace parts only as needed. If our rig had needed a full overhaul, the charge would be $75 plus parts for both first and second stages plus an alternative air source.

Full Service

For a full annual service, we turned to AirTech, in Raleigh, NC. They claim on their website that they employ factory-authorized technicians for every major brand of dive gear in the U.S. and honor manufacturers’ partsprovision warranties with proof the warranty is current. They service dive gear for some 40 retailers around the country as well as for consumers who send equipment directly.

Because we could not observe our regulator inspection first-hand and because AirTech’s website boldly states, “we are fearlessly unafraid of offering advice. Don’t hesitate to call if you want some,” we called their toll-free number.

Question: The Air II being sent to you is old and has been driven hard. Is that a problem?

Answer: We once received a regulator that had been run over by a car. The second stage housing was in pieces, but the valving mechanism was intact, so the innovative owner had simply wrapped it in duct tape (leaving access to the purge and the exhaust ports open) and continued to dive. He just sent it to us for annual service. We fixed it for him. One regulator we got in was so coated with chewing tobacco people in the next room were asking about the smell. We managed that as well. Your old Air II will not be a problem.

Question: When a regulator fails on a dive, a common comment is “I just had it serviced!” If you service my regulator and it fails on my first dive, then what?

Answer: If you didn’t damage it, then the problem is probably with our service or a defect in a new part we installed. As far as service goes, it would be nice to be absolutely infallible, but we aren’t. In recognition of this, serviced regulators are subject to careful redundant testing and inspection prior to being returned.

Regarding parts defects: every now and then, we receive a batch of flawed replacement parts. It rarely happens, but it does happen. These parts can perform well enough initially to escape detection but fail soon after. So we offer an unconditional service guarantee: if any regulator we service fails within a year, we will refund all money the customer paid for service and for whatever reasonable expenses they incurred to rent, repair, or replace their regulator while on their dive trip. We only ask for a chance to inspect the regulator, if possible, so we can identify the problem as a service error or flawed part (we notify the manufacturer). In 2004, we serviced nearly 1,200 regulators and received reports of problems on five.

It’s On Its Way

After stating that neither was under warranty, we anonymously mailed AirTech a Scubapro regulator and an Air II without the gauge console. We taped over the open port to keep out foreign matter.

Dear Editor:

I have a couple of comments on your Servicing Your Regulator article in the March issue.

1. I’ve been a victim of “just-had-the-regulator-serviced” free-flow. So have my buddies, including one just yesterday. My theory is that the seats take a little time to take a set, so the regulator needs to be readjusted after a couple of weeks. So it’s best to leave it sit at the shop for a week or two, then pick it up and test it before leaving the shop.

2. The Atomic regulators require service every two years because of a design feature: there’s no load on the seats until the tank is turned on. It’s new engineering, not new marketing, not new policy. — Chuck Tribolet (Morgan Hill, CA)


Excellent point. Newly installed seats do take time to set. Pete Wolfinger at Peter Built, which makes specialty tools for dive service, estimates that it takes as many as 250 cycles (either breaths or purge button pushes) to achieve an 80% set between the mating surfaces on both low-pressure and high-pressure seats. He sells a machine that basically will purge a regulator 45 times per minute, thus achieving the required 250 cycles in around 5-6 minutes of loud hissing noises. It’s unlikely that many service shops use one of Pete’s machines, though some technicians will basically cycle the regulator 60-80 times while adjusting the ISP and cracking effort, which should help some.

However, leaving the regulator in the shop for a week or two probably doesn’t help. First stages are designed so that the high-pressure valve stays open when the regulator is not pressurized: no cycling, no set. One idea might be to immediately hook your newly serviced regulator up to a tank, and hit the purge button around 250 times, and then see if it free-flows... If it does, have it readjusted. If it doesn’t... go diving.

Atomic regulators do have an “open seat” design; so does Scubapro. But it’s still the same with every regulator: the first stage high-pressure seat is open until pressurized. With most manufacturers, the second stage seat is closed, but regulator manufacturers like Scubapro and Atomic have a balanced design that keeps the second stage seat open until pressurized. Back in the days of old, Dacor, SP, Sherwood, and USD used to have little mechanical devices like depressors and pins attached to or built into the second stages so the owner could manually block the second stage valve from closing when he stored the regulator.

We took AirTech’s guaranteed 10-day service turnaround at $23 per stage, plus parts. We could have paid $5 more per stage for a three-day rush job or even $10 per stage for a 24-hour turnaround time. They got the gear back to us within a week. The returned packaged included the old parts in a plastic bag, so we could see which parts were replaced. They even installed a plug in the pressure port to protect it.

AirTech’s total labor charge was $69. They found a pinhole in the Air II’s mouthpiece and replaced it with a new one along with a new housing, body valve, and button exhaust. Total parts cost for both was $82.96, of which $45.13 was for the Air II’s nonstandard replacement parts.

Who Gets the Job?

If you know your local dive store and/or technician, there’s a lot to be said for the face-toface contact of dealing with someone you know personally. He may even let you watch as he runs your equipment through the tests. If no dive operator is conveniently located near you or if your local dive store doesn’t service the type of regulator you own, shipping to an operation such as AirTech’s is a good option. In both cases, our experiences excelled. Our happy ending, a couple weeks later, was taking both regulators to Cozumel, where we used them on steel 120 and 95-cu. ft. tanks filled to 3,000 psi. They performed flawlessly on dives as deep as 127 feet.

If you visit AirTech’s website, make sure and check out their “Observations” page — it’s pretty entertaining ( The site contains complete shipping instructions and other questions can be answered via a toll-free call to 866-287-0850 or by e-mail to

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