Info Function checking a regulator after service

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Thanks for the reminder of Couv, what a great guy he was and extremely smart about regulators.

When I’m getting ready for a trip (like I am coming up soon!) here’s what I do:

1. Pressurize the regulator with an IP gauge attached. Tap the purge a few times to make sure IP lockup is quick and consistent. I feel that any diver can easily learn to read an IP gauge, they are not expensive, and they are the best/most useful indicator of 1st stage health. So IMHO every diver should get one.

2. Take a few breaths off each 2nd stage. I don’t bother to measure 2nd stage cracking effort (most divers are not going to invest in the equipment needed to do that anyways) I have a decent sensitivity to how they breathe and I trust it. You can too! If it’s nice and easy to breathe and does not start free flowing, that’s good enough.

3. Leave the reg pressurized with the tank valve off for at least an hour. Then come back and check the guages. If neither have moved, that’s a good indication things are ready to go. If the SPG is at zero, there’s a leak. If the IP gauge is also at zero, that typically means the leak is not in the HP section of the 1st stage, probably a 2nd stage. Either way, it’s time to find the leak….

4. Fill up a tub, turn the tank valve back on, submerge the pressurized reg. This is where it’s nice to have a small tank so you don’t need to lift a heavy tank into the tub. But maybe you want some exercise anyways!

5. Look for the bubbles, they will be there if your gauges dropped. BTW, don’t forget to remove the IP gauge before you submerge the tank. (It’s easy to forget, care to guess how I know?) Sometimes it’s only a bubble every few seconds. Common places are the 2nd stages (out the mouthpiece), tank/regulator connection, then less common is a slow leak emanating from somewhere in the 1st stage or a hose.

I work on my own regulators so the next step for me is to fix the leak; it usually means rebuilding one of the stages, but sometimes it’s just a quick adjustment of one of the 2nd stages and/or replacing an o-ring. For a diver who has service done at the shop, it’s time to bring the reg back, explain the situation (a short video of the leak or gauges dropping is a nice touch) and hope they can fix it.

The reminder to check each hose connection to make sure none of them are just hand tight is a good one. It’s not a bad idea to use open end wrenches (or a small adjustable wrench) to just barely nudge each connection and make sure it doesn’t move. Or if you have strong hands, just try to hand-open each one. Do this with the regulator not pressurized, BTW!

Getting back to the point about 2nd stages free flowing after purge with the adjustment all the way out, but not free flowing with the adjustment in, I would say that’s generally true, but what’s more important is that the reg does not not free flow violently with just a tap on the purge regardless of the adjuster position. If it does, you’ll likely have some free flows on the surface. It means the 2nd stage is adjusted very lightly, which is nice in terms of very low effort inhalation but it can be an annoyance with 2nd stages that are not in your mouth. In my regulators, I tend to keep the IP pretty low, usually no higher than 130 PSI, and that helps to calm down lightly tuned 2nd stages. (For those who care, higher IP means greater drop at the 2nd stage, which means higher Venturi effect, which means quicker to free flow) At this point I’m getting off topic so I’ll just stop.
 
@halocline - don't forget the step #4 from Couv's list. Perform a vacuum test:

4. Watertight checks verify the integrity of the second stage. A good tight first stage dust cap is required to perform the watertight check. Alternatively, connect the regulator to a tank but leave the valve closed. Draw a breath on the second stage and hold vacuum for a few seconds. Don't draw too hard as it could collapse the exhaust valve and cause a leak. Does the regulator hold vacuum? If so, then it's probably watertight. If the regulator fails this check there may be a leak in the exhaust valve, the diaphragm, a case seal, or through a crack in the case itself

People may notice or care about a slight IP drift. But they will notice water in the mouth ;-)
 
@halocline - don't forget the step #4 from Couv's list. Perform a vacuum test:

4. Watertight checks verify the integrity of the second stage. A good tight first stage dust cap is required to perform the watertight check. Alternatively, connect the regulator to a tank but leave the valve closed. Draw a breath on the second stage and hold vacuum for a few seconds. Don't draw too hard as it could collapse the exhaust valve and cause a leak. Does the regulator hold vacuum? If so, then it's probably watertight. If the regulator fails this check there may be a leak in the exhaust valve, the diaphragm, a case seal, or through a crack in the case itself

People may notice or care about a slight IP drift. But they will notice water in the mouth ;-)
Yep, I did forget to include that, but I always do it. Thank you.
 
The tongue is used to keep the vacuum in the second stage.
This step is done with tank valve closed or dust cap on the 1st stage if the regulator is not installed on the tank, right?

To create the vacuum, inhale through the mouthpiece and then stick the tip of the tongue to seal the hole in the mouthpiece. You will feel the tip of the tongue extruding into the hole when the vacuum is created.
 
I find the easiest (and surest) way to test our regs after I'm done servicing them is to hit a local spot and do a quick, easy dive. If it's in the dead of winter, we attend a pool night and dive them that way. If it's a trip specifically for diving, my wife and I carry a 3rd complete reg set, allowing problems to be sorted at my bench once we get home. Means little to no missed diving....
 
Pressurize the regulator with an IP gauge attached. Tap the purge a few times to make sure IP lockup is quick and consistent. I feel that any diver can easily learn to read an IP gauge, they are not expensive, and they are the best/most useful indicator of 1st stage health. So IMHO every diver should get one.

The IP Gauge looks like this:

IMG_2441.jpeg
 

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