Apeks ATX 50 harmonic?

[clementyn]

hi,

have a two year old ATX 50 (DST) that has had an intermittent "harmonic" since purchase.

i bought from my local LDS during their annual sale. the shop was out of stock, so Aqualung rep delivered it later that next week. noticed on first dives with it a loud "honking" from the first stage (ie. heard to varying degrees on inhalation and bc inflation). took it straight back to the shop.

owner stated that this was not a 'rare' problem with regs in general, but that he hadn't had it on an apeks before. he checked it out and when i went to pick it up he said it wasn't reproducible in the shop, nor did it affect the bench testing. i hooked it up to a tank myself and reproduced it for him on the LP inflator with several tries. he kept the reg again and when i returned to pick it up, he stated he had 'fliped the seat.'

this seemed to take care of the problem for the first year (120 dives or so)- reg breaths like nothing else i've tried (except hubby's atx200). take meticulous care of our gear (thourough rinse after every diving day even on liveaboards). i took it in at 11 1/2 mos. for the first annual service. checked it out again on a tank before leaving the shop and it seemed fine. was ok on next several mos. of diving (another 80 dives). on our last trip tho, it started the harmonic again, this time only at the end of dives.

i am not a big consumer of air, usually ending with 12-1800 psi, so does not seem to be hi/low psi related harmonic?? although only getting the harmonic in the last 15-20 FSW and when going positive at the surface seems suspicous for this??

took it in for 'early' annual service to look at the harmonic. the LDS again finding it unreproducible out of the water and bench tests within all mfr. specs. my LDS said he tried a new "seat with a shim", but that this was only to try and eliminate the harmonic and that the reg looked like it had just been serviced within the last month or two.

am i right in not being overly worried, just annoyed, given the bench test WNL? anyone else experienced this on a DST/DS4 or another diaphram?

thanks,
lorien

 

[Diver0001]

hi,

have a two year old ATX 50 (DST) that has had an intermittent "harmonic" since purchase.

i bought from my local LDS during their annual sale. the shop was out of stock, so Aqualung rep delivered it later that next week. noticed on first dives with it a loud "honking" from the first stage (ie. heard to varying degrees on inhalation and bc inflation). took it straight back to the shop.

owner stated that this was not a 'rare' problem with regs in general, but that he hadn't had it on an apeks before. he checked it out and when i went to pick it up he said it wasn't reproducible in the shop, nor did it affect the bench testing. i hooked it up to a tank myself and reproduced it for him on the LP inflator with several tries. he kept the reg again and when i returned to pick it up, he stated he had 'fliped the seat.'

this seemed to take care of the problem for the first year (120 dives or so)- reg breaths like nothing else i've tried (except hubby's atx200). take meticulous care of our gear (thourough rinse after every diving day even on liveaboards). i took it in at 11 1/2 mos. for the first annual service. checked it out again on a tank before leaving the shop and it seemed fine. was ok on next several mos. of diving (another 80 dives). on our last trip tho, it started the harmonic again, this time only at the end of dives.

i am not a big consumer of air, usually ending with 12-1800 psi, so does not seem to be hi/low psi related harmonic?? although only getting the harmonic in the last 15-20 FSW and when going positive at the surface seems suspicous for this??

took it in for 'early' annual service to look at the harmonic. the LDS again finding it unreproducible out of the water and bench tests within all mfr. specs. my LDS said he tried a new "seat with a shim", but that this was only to try and eliminate the harmonic and that the reg looked like it had just been serviced within the last month or two.

am i right in not being overly worried, just annoyed, given the bench test WNL? anyone else experienced this on a DST/DS4 or another diaphram?

thanks,
lorien

I think these kinds of things are usually caused by vibration. I don't think it means that your reg is about to explode but personally It would bother me to dive with it if I didn't think it was perfect. You might be able to get rid of the problem permanently by swapping out the main spring with a new one. Sending it back to the manufacturer for warranty service might give you better results than your lds' regulator tek.

R..

 

[Greg Barlow]

I agree with Diver0001. In many of these frustrating cases, simply flipping the spring takes care of the harmonic sound. I had one second stage that would "hum" at certain times, and usually only when deeper than 100' or so. I rebuilt the second stage and the problem stopped (apparently the spring was flipped during the work). Well, on the next rebuild it began its music again. At the end of that dive, I broke down the second stage and flipped the spring. The musical side of that reg has not returned.

This type of problem is not uncommon with any type of reg. Often times it originates from the surface ground ends of the spring and the way in which they interface with the parts. A small vibration begins and then resonates through the stage.

It normally doesn't cause any problems, it is just as annoying as all get out.

Greg

 

[LUBOLD8431]

hi,
he stated he had 'fliped the seat.'

my LDS said he tried a new "seat with a shim", lorien

These two statements have me worried. Since, they are both not possible with an APeks reg. The HP seat only goes one way, and there are no shims to add anywhere to the reg.

He might have been talking out of his butt to impress you, or he has no clue what he is doing with Apeks regs. I might be looking for a new service tech.

And, the other guys are right. Most of the times a harmonic comes from the spring. Either by flipping the spring, or applying a light coating of grease, or changing the spring entirely might solve the issue. I have four Apeks, and none of them make any noise like you describe.

 

[Genesis]

BTW Oceanic not long ago had a bulletin out saying that some of their regs had this problem and to bring them in immediately as apparently they had a concern that the harmonic vibration might cause the main spring to fracture. If it was to do that, the reg would lock up instantly (no gas!)

My G250s do this out of water (the exhaust diaphrams vibrate) but not once submerged. None of my first do it.

 

[Zaphod]

ScubaPro firsts are notorious for "honking" and their suggested solution is to flip the spring, along with rearranging the shims (if there's more than one shim, make sure one is on either side of the spring). I would agree that these fixes just won't work with an Apeks reg, so the LDS may have gotten confused or is just clueless. In my time servicing Apeks regs, I've never heard of one honking, but I have seen virtually all brands of piston firsts with the same issue.

 

[clementyn]

thanks for the input. i will call my lds owner/tech on the seat filp vs. spring flip and see what he has to say. if the reg starts reproducing the harmonic, i'll probably follow your advise on requesting waranty service.

hmm, anyone know off the top of their head how long apeks are under waranty? i'll have to go dig thru my files to find my receipt and docs.

thanks,
lorien

 

[LUBOLD8431]

Apeks=Lifetime warranty for 1st and 2nd stage service kits (serviced every other year, and if it needs service in the off year, you pay for parts)... You pay for labor...

 

[Pao]

I have the same problem. I flipped the sparing and it helped for a while. But the noise is back again. Anybody know where I can get a replacement spring?

 

[Nemrod]

I would request a new spring be installed. Your shop will not do it but on MkV and similar firsts that have done this vibration, I have removed the spring, pressed it in a vice to solid height and then shimmed with a thin nylon/mylar shim/washer. Another trick that they will be totally clueless at is to remove the spring, hone both ends of the spring with rouge or grinding compound, polish and reinstall with silicone lubricant coating each spring face. The idea being to improve/increase the surface contact area of the spring flats to the regulator body.

Also make sure the first stage piston O-ring is lubricated (water generally acts as sufficient lubricant, the reason most stop this honking once submerged) with silicone or correct grease.

N