Dive Rite DSV 300

[rdsmith66]

So, while cruising the interwebs searching for a DSV to adapt to a PRAM, I came across this:

http://www.diverite.com/products/catalo ... drt-dsv300

The trouble is, this DSV was designed to work with 1 1/4" hose ends. I see three possible solutions:

1. Fashion new hose connectors to accept 1 1/2" hoses;

2. Build up the outside diameter of the connectors to 1 1/2" (possibly with a sleeve of 1/8" rubber cemented in place, or a piece of delrin turned to an outside diameter suitable for a 1 1/2" hose, epoxied in place); or

3. Stretching 1" hoses over the ends.

Your thoughts? Is this feasible, or shear folly on my part? Any other suggestions?

Ralph

[DaleC]

Hi Ralph,
Maybe I'm missing something obvious (wouldn't be the first time) but is there any reason you don't want to use a USD mouthpiece ($25 in the store)? That rebreather mouthpiece probably costs a fortune.

[rdsmith66]

Hi Dale,

No, you're not missing anything obvious. I'd just like the ability to shut off the air from the mouthpiece, for a variety of reasons. I've read here where others have created their own DSVs from parts sourced at their local home improvement store, but I'd like something a bit more polished. You're correct: the rebreather mouthpiece is relatively expensive (more than I paid for a RAM), but it's manageable.

Ralph

[DaleC]

I see.

The main problem I would like to overcome with my mouthpiece is the tendency for freeflow while on the surface doing a swim but I am looking to making a mouthpiece plug out of rubber rather than a cutoff for the air. Luis on the board here has made them (where I got the idea).

[rdsmith66]

That is also one of the problems I would like to address. It's simple enough to get some dental alginate to make a nice, precise mold, and form a plug from RTV rubber. But, there are other scenarios where I'd just like to close it all off without requiring a separate plug dangling around.

Ralph

[Gilldiver]

Contact Louis, he has both a DSV and plug design and uses both. I know he prefers the plug.

[Herman]

If you have access to a lathe, it should not be too hard to turn the ends of the Dive Rite DSV off and thread the length of it. Then turn a delrin or pvc spacer ring to go over it, threading it internally. An oring or soft rubber gasket at the DSV-spacer junction should be plenty to seal it.....or don't bother threading them and just glue them (silicone??) together.
Have you seen the DSV that Luis made a while back?? Basically it was a standard straight mouthpiece with an internal barrel that turned to open and close the mouthpiece. It was a lot cheaper and fairly easy to construct plus it looked almost "normal".

[antique diver]

Ralph, your idea to build up the diameter of the connection worked for me in a related situation. My Spaco reg has hose horns about 3/4" in diameter, and I wanted to build them up to use regular 1" hose ends.

I used several layers of bicycle inner tube cut to an appropriate length, then just pulled one over the other until the correct diameter was achieved. Seems like I have about 3 layers, but I can't even see them with the hose clamped on. I never found the need to cement them together since they stay put just fine if you use a snug fitting inner tube diameter. Once the hose is on and clamped in place, the inner tube spacers aren't going anywhere, and don't even show.

I have dived this rig many times with no problems. Good luck with your project... I like the idea.

[YankDownUnder]

A cheaper solution............

I have 6 rebreathers and see no need to put a petcock or DSV on my open circuit regulators. However, I have experienced free flow on the surface when using double hose regulators. When I began diving in 1959 we would snorkel to the site, have our dive buddy turn on our air and then descend. I didn't like relying on a dive buddy and I often dived alone anyway. The solution for me was to undo the chest strap on my harness and slip the mouthpiece inside. I could swim to my site and back and the mouthpiece stayed right where I wanted it to stay.

An Aside..The other guys who dived with Porpoises, Sea Bees, and Scubmatics all had a similar problem. Their mouth piece regulators had long hose because tanks were always carried inverted, so they could decant. The neck strap was added by Porpoise and by Sea Bee. Dropping a mouth piece regulator (single hose) meant it fell to where your feet were, and because of the venturi, a lot air was often lost.

When I first began to dive, I had a Healthways harness and I dived a Heinke MkIII. The blue harness had a set of snaps holding the left shoulder harness. I undid the snaps, slipped the left hose underneath and snorkeled out that way. If I had a problem and needed air, I could pull the mouth piece up and breathe, and release the snaps if it suited me.

I think Mike Nelson just held his mouth piece down. With experience it's less of an issue.

Anyway, it was just a thought on how we actually dealt with the problem back then. Steve

[simonbeans]

Diving vintage generally is referred to as diving with vintage equipment. I personally do not consider a Phoenix a vintage regulator. It is a modern double hose regulator that has allowed divers to use a double hose regulator in a situation where period vintage gear would not be possible. To dive vintage requires techniques and skills of the period during which the equipment was used. Unfortunately it seems to be easier today to utilize some modern accessory to circumvent a skill that was necessary with vintage dive gear. To continue to add modern parts to a double hose regulator seems to me to diminish the aura of vintage. A reproduction part that takes the place of a original is acceptable, as original parts are becoming more and more scarce. But when a correct reproduction is available, then trying to utilize some modern part to correct a perceived issue is not in my opinion part of vintage diving. I would think that learning how vintage divers performed various skills would be better.

[luis]

A couple of years ago I talked to Dive Rite reps at the Boston Sea Rovers Scuba show. At the time, in order to buy the re-breather DSV valve you had to buy a re-breather, which meant that you had to get certified for that re-breather.

I asked them how about buying them just as a spare part. They said you had to send back the damaged DSV from your Dive Rite re-breather.

In other words, they did not want their DSV valves being used for any other application other than their re-breathers. At the time they did not want the liability of their re-breather parts being used on a home made re-breather or any other application. Can you buy this DSV valve by itself now?


BTW,
I think it was the Northrill regulator that had a DSV type of valve, so you can’t really say that a DSV is not “vintage”.

[rdsmith66]

Can you buy this DSV valve by itself now?

Officially, no.

[Nemrod]

Hi Ralph,
Maybe I'm missing something obvious (wouldn't be the first time) but is there any reason you don't want to use a USD mouthpiece ($25 in the store)? That rebreather mouthpiece probably costs a fortune.

It is an advantage to be able to close the mouthpiece off to prevent the regulator from free flowing when surface swimming on the back as many of us are fans off. Even if belly swimming with a stink'n snorkel every time I surface and pop my mask back on my forehead so as to see where the Hades I am going and what boat or jet ski is about to run't over me and a wave washes over me the stupid regulator goes nuts and it is most annoying.

Nemrod

[YankDownUnder]

"swimming on the back"

The reason we used snorkels was perhaps because we were primarily snorkel divers back then. Very few of us had a second tank. Our tanks were usually only made for 1800 psi and compressed air filling stations were few and far between. Normally we would snorkel an area and then our second dive was with scuba, to access areas that could not be otherwise reached. Nobody wasted air on an unknown area.

The snorkel was considered basic safety equipment. Entering the water without one brought as much condemnation as a PADI instructor might unleash on you today, for having your mask on your head. (Which is were mine always is, when I surface.) The mask went up so we could breathe through our nose. We kept the mouth piece in to prevent the free flow of air.

The reason we did not swim on our back was because the danger was perceived to be from below. Swimming on your back means you are swimming blind. We generally shore dived and shallow water was an issue. We needed to fend off "bommies" and other rocks, large and small. We used the little channels so we could swim in as far as possible before standing up. We also didn't want our regulators to hit anything behind us.

I always used my hands to 'walk' the last few yards, so I could stand up in shallow water. Standing up in chest deep water meant the surf would knock you over. We were also concerned about sea life. Sharks were a worry, but most have been killed off now and probably weren't the threat we thought. Large sting rays are still not something you want under you either. Here they can be 6 or 7 feet across.

Something I have noticed on Scuba Boards and some other sites, is the stigma attached to snorkeling. I believe that it is not perceived as being 'macho' and it gets left behind. We did not have the luxury of charter dive boats, or hardly any boats at all. Leaving my snorkel behind was something I would never do. My snorkel is still securely attached to my mask whenever I dive, and it is some 50 years later. Steve

[Nemrod]

I never much used snorkels, don't have much use for them then or now. Each to their own but the answer to the post of why a DSV remains, some of us prefer to swim on our backs for distance on the surface and nowadays it is even more important with so much boat and jet ski traffic. My dive the summer before last where I swam out to the third reef line from WPB and was in the water for several hours and covered several miles led to several encounters of the jet ski type, and Yank. you would be proud, I think I took along a snorkel and actually used it through the minor surf and for conserving air as I spied out the best places to dive. they have a use, I stuck it through my weight belt.

James