How keep water from entering First Stage

[Jim Lapenta]

I haven't seen the manual, but I'm guessing that they are concerned the air pressure from blowing off the reg with compressed air might defeat the Dry Valve Technology and force water into the reg. Does that make sense?

THis is exactly the reason for this. The dvt will with stand about 8-10 ft of submersion depending on the spring. It is not designed to keep out water if you drop it off a boat in 30 feet plus. The air coming out of the tank valve is at what, say on a low tank 500 psi. Hit the bullet with that kind of pressure and the dvt feature is negated. I'd have to look at the manual to see just what the min opening pressure is but I'll bet it a LOT less than that. Otherwise when your tank got to 400-500 guess what? Like the old jvalve no air. But in this case no rod to pull. The dvt is designed only to keep out water that could get in under the pressure it would be subjected to if you dropped it in a rinse tank with the dust cap off.

 

[keyshunter]

THis is exactly the reason for this. The dvt will with stand about 8-10 ft of submersion depending on the spring. It is not designed to keep out water if you drop it off a boat in 30 feet plus. The air coming out of the tank valve is at what, say on a low tank 500 psi. Hit the bullet with that kind of pressure and the dvt feature is negated. I'd have to look at the manual to see just what the min opening pressure is but I'll bet it a LOT less than that. Otherwise when your tank got to 400-500 guess what? Like the old jvalve no air. But in this case no rod to pull. The dvt is designed only to keep out water that could get in under the pressure it would be subjected to if you dropped it in a rinse tank with the dust cap off.

That was my immediate thought. People seem to get pretty wild when blowing water off of dust caps. If one happened to direct the flow directly into the inlet, the dvt would be negated. Since the dvt seal should keep out any water residing in the dust cap, safer to say don't use hp air to blow off the dust cap. The CDX5 I had did not have a dvt, but had the usual very deep Oceanic dust cap. I pretty much had to use hp air to blow out the water. But, there is a technique for not blowing the water into the reg inlet.

 

[halocline]

I used to use tank air to dry off the dust cap, but I don't anymore. I've seen too many people actually driving water into the filter with the tank air. Now I wipe off the reg, or even pour a little fresh water over it while it's still on the tank. Then I remove it and just blow the water out of the dust cap with my breath. It's much easier to control.

It's actually not the water as much as the salt entering the filter that's the real problem.

 

[beester]

This is what I do:

- Blow out the water of the dustcap using just my breath (not tank) or dry with towel.
- Put dustcap on 1st stage (din) for transportation home
- Home rinse regulator (depending if I've dived salt or fresh water).
- Store regulator without dustcap attached (open), and with 1st stage opening faced downwards

Reason for storing regulator without dustcap. Where I keep it, it won't collect dust. It won't collect water if I leave the 1st stage open and turned downwards. However with the dustcap in place it would collect water purely by condensation alone.


Try this... dive in cold water with your reg. Thoroughly dry the dustcap and put in place. At home rinse regulator, then dry dustcap again and put back in place. After some days you'll see if you remove the dustcap that the 1st stage opening still has some condensated water droplets near or in the opening. If you store without the dustcap these droplets will just evaporate away.

My 2 cents.

 

[Belmont]

You could always keep the dust cap off of the first stage....ie, cut the rope or rubber holding the dust cap on your reg. Leave it on the boat, put it back on when you get out of the water, it never gets water on itself.

Exactly that, leave it in your goody bag, it makes for less dangly things to catch on something. That cap is to protect your reg when you are out of the water.

Contrary to what some people think there is pretty good diving in the St-Laurence river good viz in the summer and all things considered reasonable temps from july to september. Come down to the Thousand Islands.

 

[tfsails]

I rebuild Aeris (Oceanic's twin) regs and have done many with DVTs installed. To me, the DVT is good enough to keep casual water such as drips, mist from drying the dust cap, etc. from entering the first stage. It is not intended to be waterproof even in a rinse tank. If I owned one I would not rinse it without the regular dust cap dried out and properly installed over the opening.

It's been my experience when testing a DVT reg that the presence of the plug and spring make for a slightly different sound as the LP air in the reg is sent to the second stage. It takes a little vacuum (relative to the tank side of the connection) inside the HP side of the first stage to get the plug to unseat and allow more air from the tank to enter. This results in a fairly slow hiss of air that may be disconcerting to some divers. I've had several customers complain about the noise and may even have one ask me to disable the DVT because of it. She hasn't made that decision yet but I expect her to soon.

When the first stage goes into "lockup" and internal pressures are steady, the DVT plug will seal up just as tightly as physical clearance between it and the tank valve will allow. This is the cause for the delay and the hissing described above when the diver inhales from the second stage. This hissing sound is entirely normal and nothing to be concerned about assuming the reg is working properly.

 

[Potapko]

I also leave my dust caps in the goody bag on the boat or on shore. Why take something into the water that you want to be dry?

 

[diverrobs]

Belmont:
I have a cottage just outside Napanee. I will definitely be in the St. Lawrence this summer. Napanee is perfect. 1 hour to Kingston, 2 hours to Brockville, 1.5 hours to Picton. I plan to get a few dives in eastern ontario this summer.

Rob