help explain what LDS shop reported about my second stage?

[davidbaraff]

I brought my regulator (XS-Scuba Trimetal) to my shop for its annual check, prior to going on a dive trip to hawaii. They called me and said it passed, the technician said its safe to dive with (or he wouldn't be returning it).

But they cautioned me that the second stage is at the "high end" of its pressure, measureing 148 PSI. (The highest acceptable range being 150.) I'm not sure what the lowest range is. They're saying I should have it overhauled after my hawaii trip. (Due to timing constraints, I brought it to a place that doesn't service XS-Scuba, and they were very upfront about telling me if it had a problem, they wouldn't service it for me since they can't get the parts. I told them that's fine, I want to know if its safe --- if not, I'll use something else in hawaii). So I'm not questioning at all what the LDS is doing, just trying to get a translation into English of what's going on here...


Can someone explain what it is they're trying to tell me? The first stage is supposed to reduce things down to 150 PSI above ambient, so why is measuring 148 at the second stage at the high end?

Also, the shop said that when you do an overhaul of a regulator (they called it a rebuild) you should expect to pay around $100. (I assume that's mostly labor -- seems like the parts are around $25?). Seems like i could buy a brand new second stage (not first stage) every two years and always have a new regulator and never have it overhauled? (The way i dive, i think an overhaul of once every two years would be plenty, with a bench check of once a year.)

Anyway, just trying to understand what's going on here... Thanks for any advice.

 

[ReefHound]

Buying a new second stage (remember, you have two of them) doesn't remove your need to service and maintain the first stage.

 

[ddown]

The 148 number is the intermediate pressure which the first stage provides not the second stage.

 

[DevonDiver]

They called me and said it passed, the technician said its safe to dive with (or he wouldn't be returning it).

I think that's called theft.

 

[scoobydrew]

Hey there,

Regulators have to break the pressure down from what it is in the tank to something more breathable in order for us to use it, on modern standard regs this is done in 2 stages - the first is called the first stage, the bit you attach to the tank and the second is called the second stage, the bit that goes in your mouth.

The first stage needs to convert from tank pressure to a specific pressure referred to as the intermediate pressure, this is normally between 140-150 psi but can vary from design to design, 145 is probably the most common setting.

If the intermediate pressure is too high then the second stage will free flow, if it is too low then you will not be able to breath from it.

148 is not a huge concern in itself but does need watching. if something inside is not right then the IP will contiinue to rise untill eventually you start getting a gradual leak from whichever is set the weakest out of your primary second stage and your octopus.

If the IP is out then the symptom will be recognised in the second stage but the problem will be in the first

 

[herman]

I did a little looking and if your reg is what I found, bottom line it's no big deal. Like others have said, the 148 is the IP that the first stage is putting out. As long as it's stable (stays at 148 and does not increase) there is nothing to worry about. While it may be at the top end of the recommended range, the second stage appears to balanced (and at least the on I saw was adjustable) so it can easily handle a few extra PSI and if the second stages were tuned at that pressure then it makes no difference. I set most of my regs to 145 anyway so I would not take a second look at 148.

As for it needing a rebuild, as long as the IP is stable ....the IP stays put at 148 and does not increase, returning to 148 each time you apply pressure or breath from the reg, I would not rebuild it. What the value is, within reason, is not nearly as important as whether or not it stays constant. An IP set a little low or high is no big deal, if it goes to 135 for example, then slowly increases to 148 (called creep) or locks up at different values each time, that is a problem than needs to be fixed. IP is something you can and IMO should monitor yourself. You can get IP gauges that snap on you LP inflator hose for under $25 that will tell you all you need to know as the end user. They may not be adequate for bench work but for keeping an eye on your regs IP, they are fine. Middle Pressure Gauge, Piranha Dive Manufacturing The $100 you were quoted sounds more like the cost of an entire rebuilt, 1st and 2 seconds, not just one second.

 

[Capt.Gene]

I think it's always a better idea to seek service from an authorized dealer.
And if the repair tech hasn't had specific training on your reg I say walk.
Ask the questions before you drop off your regulator for service.
Training and competancy go hand in hand.

 

[redacted]

I think it's always a better idea to seek service from an authorized dealer.
And if the repair tech hasn't had specific training on your reg I say walk.
Ask the questions before you drop off your regulator for service.
Training and competancy go hand in hand.

The only requirement to become an authorized dealer trained tech is to work in a shop that is a dealer for that brand. Nobody fails the one or two day training course. That system produces many competent techs that are capable of doing an adequate job on your regulator. It also produces certified techs that might be challenged to change a flat tire. Other than experience with that shop, I'm not sure how a diver can tell the difference. The better tech can service any regulator. If you can't DIY, then look for the techs by reputation and experience, with secondary consideration of certification.

As far as the 148 psi IP goes with a balanced piston reg, I would not be happy with that. But the real issue is how did it get to 148 (close to the top of the spec range. If it was set there to begin with rather than around the more common setting of about 135 then it should be fine but I can't imaging why any tech would set it like that. If it is settling in on 148 after a period of creep, it will just get worse until it starts to vent through a 2nd stage. This is not a catastrophic failure but and indicator of a reg that needs to be serviced. It will most likely not be a problem for one more trip. In fact, I would prefer to dive that reg rather than one just back from service by some unknown tech. Any problem likely to develop during your trip should be mild and of little consequence.

 

[DaMaDo]

You could also get one of these and keep an eye on it yourself. I test mine like once a month. For $15 (used to be $9), I like to know. The manual for the regs should state what the IP is supposed to be for your particular brand and model.

 

[davidbaraff]

My understanding is that the acceptable range is 140 -- 150, and the usual target range is 145. So 148 is close.

I agree that if the target was 135, then 148 would be alarming. But I think it was supposed to be set to 145 -- that's what the tech guy said they're generally set to.