Acquired used Oceanic CDX5 / GT3 (plus Omega II) with DVT, any opinions ?

[scubafanatic]

I recently acquired this reg set, in what appears to be essentially new condition, haven't dove it yet. I was really only after the Omega II 2nd stage, but it was so reasonably priced I bought the whole set. I've never owned an Oceanic reg set, nor a reg equipped with 1st-stage DVT. The GT3 2nd-stage admittedly looks pretty cheap/plasticky (compared to my metal SP 109/156's and Atomics, for example) but since it has 'DVT' I may use this reg set for 'rough conditions' trips where gear is more likely to be abused (by either the dive conditions or boat crews). That being said, does anyone have any opinions on this reg set with respect to things like performance and reliability ? Any issues with the 'DVT' feature ? Any recalls I should know about ?

Thanks in advance!

 

[axxel57]

I recently acquired this reg set, in what appears to be essentially new condition, haven't dove it yet. I was really only after the Omega II 2nd stage, but it was so reasonably priced I bought the whole set. I've never owned an Oceanic reg set, nor a reg equipped with 1st-stage DVT. The GT3 2nd-stage admittedly looks pretty cheap/plasticky (compared to my metal SP 109/156's and Atomics, for example) but since it has 'DVT' I may use this reg set for 'rough conditions' trips where gear is more likely to be abused (by either the dive conditions or boat crews). That being said, does anyone have any opinions on this reg set with respect to things like performance and reliability ? Any issues with the 'DVT' feature ? Any recalls I should know about ?

Thanks in advance!

The 1st stage has the DVT feature, not the 2nd stage.

The GT3 has a classic down stream valve, breathes usually reasonable, just the plastic of the housing brakes faster than other brands when used extensively as fleet reg.

Otherwise concerning the DVT that's all I found:

News - DVT Quality Alert

Good luck!

 

[halocline]

Not only is this a 'solution in search of a problem' it's apparently a 'bigger problem in search of a smaller problem'.

Who possibly could have seen that putting a plastic ball directly in the air path at the tank valve might not have been the best idea?

 

[scubafanatic]

The 1st stage has the DVT feature, not the 2nd stage.

The GT3 has a classic down stream valve, breathes usually reasonable, just the plastic of the housing brakes faster than other brands when used extensively as fleet reg.

Otherwise concerning the DVT that's all I found:

News - DVT Quality Alert

Good luck!

I plugged in my 1st stage serial # and it didn't show to be one of the affected units....so, so far, so good. Thanks for the link!
---------- Post added October 27th, 2015 at 01:15 AM ----------

Not only is this a 'solution in search of a problem' it's apparently a 'bigger problem in search of a smaller problem'.

Who possibly could have seen that putting a plastic ball directly in the air path at the tank valve might not have been the best idea?

If memory serves, both Oceanic and Aqualung use/used a version of 'DVT' technology, both long standing, established scuba gear manufacturers, so I'm not sure it's a completely crazy idea. I remember reading reports (years ago) of some divers complaining of assorted squeaks/noises while diving associated with DVTs, so that would be my main concern now. My plan is to use this reg set as a back up/emergency loaner reg, or a reg I wouldn't be too upset if it were dragged/abused by a boat crew/dive op on a trip to a rough/primitive location, with the DVT feature an added bonus for such situations, assuming the reg set is a decent performer and reliable.

 

[keyshunter]

Do not confuse AL and Oceanic's versions of a first stage closure device. The only similarity is that they both use a spring for closure. The AL version (ACD) is held open mechanically by the first stage's connection to the tank valve. It is held open until the first stage is removed from the valve. Oceanic's version (DVT) uses what is essentially a spring loaded ball which opens and closes with gas pressure. IMO AL's version is far superior.

 

[Bob DBF]

Do not confuse AL and Oceanic's versions of a first stage closure device. The only similarity is that they both use a spring for closure. The AL version (ACD) is held open mechanically by the first stage's connection to the tank valve. It is held open until the first stage is removed from the valve. Oceanic's version (DVT) uses what is essentially a spring loaded ball which opens and closes with gas pressure. IMO AL's version is far superior.

Does anyone know at what pressure the DVT decides you don't need air anymore air? It sounds like a J-valve without the reserve lever. I'd be inclined to disable that particular "feature".



Bob
---------------------------------------------
... you've got to ask yourself one question: Do I feel lucky? Well, do ya, punk?
Harry Calahan

 

[keyshunter]

Bob,
Early on, I read that 15psi is necessary to open the DVT, so I doubt that low air pressure would be a problem. Of course, that is for a clean and not salt blocked DVT. Also early on, there were several redesigns of the ball shape, since they were quite noisy in use. I recall diving in the Caymans with an instabuddy who had a one. It whistled so loudly, that I could hear every breath she took. When I returned from that trip, I spoke to a friend who was an Oceanic dealer. He said that to fix the noise problem, he had removed several DVT's from customers regs and they were fine.

 

[halocline]

Because the oceanic DVT uses a ball-on-a-spring directly in the air path, it's closed whenever the pressure between the tank valve and the HP chamber of the 1st stage is equalized. It only opens during demand, and only opens enough to maintain the slight pressure imbalance that it needs to open. Since the tank valve itself is the bottleneck for air flow with any reasonably high performance regulator, it's a really poor idea to place an additional flow restriction in that spot. When it's working perfectly, I suspect that there isn't any noticeable effect (other than the noise) on breathing, but I bet under high demand there are temporary additional drops in IP as the tank valve struggles to re-supply the HP chamber.

Another really dumb thing about it is that it makes it very difficult to inspect the filter before each dive. I always have a quick look at the filter before connecting my reg; it only takes a fraction of a second and lets me know if there is anything that's accumulated on the filter from a wet fill. This sort of thing happens more often than you might think, and it can really slow down air at depth.

If I owned one of these regulators I'd remove the DVT immediately.