Should I Be Concerned?

[honeylager]

A while back I purchased a set of regs off here:

Mk25/S550 with an old model Sherwood Oasis, pressure gauge and an LPI hose. When they serviced the regs at my LDS they told me immediately when they put air in it the hose on my S550 almost exploded, so I replaced that. Furthermore my LDS doesn't service sherwood products so my octo hasn't been serviced in who knows how long. Anyway my concern is that when I'm diving if I look toward the surface my mouth is full of water (with the regulator in of course) and if I try to breath while looking up my airflow stiffens a fair amount. Lastly, I was diving in El Nido and at around 32 meters my S550 started hissing for a while until I went up to around 28 meters. However I dove them to 39m in Coron without that problem. Any insight on this issue? I'm not sure If I should replace either or both.

Thanks,

Shane.

 

[halocline]

The part about getting a mouthful of water when you look up is due to the 2nd stage leaking water in. You don't notice it when looking down because the water just drains out the exhaust valve. It's either a poorly sealing exhaust valve, a problem with the mouthpiece, or possibly a torn diaphragm or even a cracked case. The dive shop that serviced it should have tested to make sure it holds a vacuum; it takes all of 5 seconds to do that. With the dustcap on the MK25 tightly in place, try to draw some air on the S550. If you can, (likely given what you've said) there's a leak and it should be fixed.

The part about it breathing harder when you look up is a normal part of regulator function. It has to do with the geometry of the reg. Despite what someone is sure to post, it does not have to do with the depth of the regulator relative to your lungs, whatever that depth might be. (At least I really don't think so, and I have very good reasoning) There are lots of threads about that, and the reg/lungs bit is an old assumption. Short answer; it's normal, don't worry about it.

The "hissing" at depth you're referring to is a freeflow, correct? There's no particular reason I can think of that it would flow at 32 meters but not at 28, and as you mentioned, it's inconsistent. If the reg is tuned very lightly, it could start to flow a bit in certain positions; also due to the geometry of the reg. Turn your VIVA knob to minimum and see if that helps. If the "hissing" is not a freeflow, but more like a honking or wheezing with no associated bubbles, it's probably a resonance issue in the first stage piston. Annoying but harmless, and not that uncommon.

The hose "near explosion" sounds kind of odd. The hose should never see pressure higher than 135 PSI or so; if it does, there's a very serious problem with the first stage. Otherwise, maybe they were just saying that the hose was worn and ready to fail. Hardly an "explosion", but I guess that kind of explanation can impress upon you how brave the tech is and how vital to your well being.

There's probably no reason to replace the regs, just the tech that worked on it. Or, at least bring it back and ask them to check for leaks in the 2nd stage.

 

[Couv]

You should be very concerned. You need a new reg tech. Here are some checks you can do yourself:
http://www.scubaboard.com/forums/regulators/346813-regulator-inspection-checklist-rev-7-a.html

 

[ams511]

There is nothing special about a Sherwood so I an not sure why the tech refuses to service it.

 

[Bubbletrubble]

There is nothing special about a Sherwood so I an not sure why the tech refuses to service it.

Well, if the reg tech is not trained to work on a Sherwood, he could open himself up to additional liability by working on it.
Sherwood first stages have a rather unique design that can make them more problematic to service. It's possible that this has led to the dive shop having a blanket policy to not attempt to work on any Sherwood regs at all.
Not being an authorized repair outfit, he might not have easy access to Sherwood parts either.
For these reasons, it's not uncommon for a dive shop to decline to work on a brand of reg that its servicing department is not trained to work on.