Regulator checklist and inspection

[herman]

Couv, I just ran across a minor change that may should be done to the checklist.
Note 6 reads as follows"

6. Check for air leaks by putting regulator on a tank and with the pressure on, first listen to any leaks, then turn the tank valve off but do not purge the reg. Note the SPG pressure and leaving it undisturbed come back in 5 or 10 minutes. The SPG pressure should be close to the original value. A drop of 200-400 psi is no big deal, but a large drop in pressure indicates something is leaking beyond the normal limits. If the leak is so fast you can see the needle drop just looking at it, the leak is probably large enough to warrant fixing before you dive

When responding to another thread about an Oceanic that turned out to be a Sherwood, the check list was mentioned. When I read this part it occured to me that the leak test is not totally applicable to Sherwoods since they "leak" on purpose and that will greatly affect this check. I think a special note may should be added to exclude Sherwoods from this step or at least make a note that they will tend to drop pressure faster than other regulators and that for Sherwoods, a slow leak (in the correct place obviously) is not only normal and the lack of one indicates the reg needs servicing.

 

[Luis H]

I don't have a lot of experience with Sherwood, but my impression is that the 200 to 400 psi drop in 5 to 10 more than covers the Sherwood. At least that what I had in mind when we were writing this.

That being said, it would make sense to make a comment about the unique response of a Sherwood.

 

[Couv]

Good eye, Herman. Like Luis, I was under the impression that 200-400 psi drop over 10 minutes (after closing the tank valve) would still be satisfied even for Sherwoods. However, as both of you have pointed out, a note mentioning Sherwoods is probably in order. It's been a while since I last read over the checklist, perhaps it's time for a REV 8....keep the ideas coming.

BTW, I don't have a Sherwood so if you're in an experimenting mood and want to give me a ball park figure, that would be appreciated.

 

[herman]

I think I still have an old Magnum some where, my first reg actually....let me see what I can do.

 

[guruboy]

So my 2nd stage is failing the vacuum test. When I inhale, I can hear airflow.

Any suggestions on how to find the cause?

It's an Atomic ST1.

 

[Couv]

Hi Gunboy,

Sometimes a regulator will fail the vacuum test because you are actually drawing air through the opposite second stage. On way to find leaks in a second stage is simply to remove it from the hose and put your thumb over the fitting where the hose attaches. If it still leaks air remove the cover over the exhaust valve. Make a seal with your lips over the exhaust valve and blow. If no leak then you may have a small leak in the main diaphragm. Remove the cover and hold it up to a light to check for any splits or cracks. Gently stretch the diaphragm while looking for anomalies. If still no problems found, check the o-rings that make a seal for any of the fitting or flow vanes that go into the case. If you still don't find any issues, use a bright light and a magnifying glass and look over the case for any cracks. One place in particular if you have a plastic case is where the air barrel goes into the case. This happens because people over torque that fitting and fail to use two wrenches when removing a hose.

Good luck and keep us posted.

Couv

 

[guruboy]

Thanks, Couv!

I'll play around with it this weekend.

Maybe I could just remove the reg in question and plug the intake on that instead?

 

[Luis H]

Hi Gunboy,

Sometimes a regulator will fail the vacuum test because you are actually drawing air through the opposite second stage. On way to find leaks in a second stage is simply to remove it from the hose and put your thumb over the fitting where the hose attaches. If it still leaks air remove the cover over the exhaust valve. Make a seal with your lips over the exhaust valve and blow. If no leak then you may have a small leak in the main diaphragm. Remove the cover and hold it up to a light to check for any splits or cracks. Gently stretch the diaphragm while looking for anomalies. If still no problems found, check the o-rings that make a seal for any of the fitting or flow vanes that go into the case. If you still don't find any issues, use a bright light and a magnifying glass and look over the case for any cracks. One place in particular if you have a plastic case is where the air barrel goes into the case. This happens because people over torque that fitting and fail to use two wrenches when removing a hose.

Good luck and keep us posted.

Couv

One more thing to check is the mouthpiece itself and the joint between the mouthpiece and the tube (including the tie strap). Is the mouthpiece the right size for that tube?


Also if you pull too hard you could be folding the exhaust valve (I can't remember if this was covered on the check list).

 

[Couv]

Thanks, Couv!

I'll play around with it this weekend.

Maybe I could just remove the reg in question and plug the intake on that instead?

Yes, sorry I was not clear-that is what I meant. Remove the regulator in question, put your thumb over the opening and try again. But again, there may not be a real problem as the "leak" may actually be air coming all the way from the other second stage. Is it breathing wet?

 

[guruboy]

I just had it serviced in june and haven't had any issues with it yet. Just found the checklist and figured I'd give it a try.