Upstream Valve Concern

[CoalBoy]

Doc Ed,
thanks for the link. I checked out the "screw-on" OPV NetDoc was talkin' about.
goes for $24 (based on DR Express). i'll consider gettin' one sometime(if i can get it here in the phils.) just to be "fail-safe."

 

[DA Aquamaster]

About the hoses, are we talking about "explosive" hose rupture?
My concern is that i extended the hose that came with the jetstream(~4ft) using a diverite hose(~3 ft) and coupling.

If the OPV came integrated in the poseidon hoses, then in case of HP failure, the rupture will be on the "poseidon" side, and not the DR side, right? This concern is for diving doubles.

No worries when diving singles, as i use the (long hose) Jetstream and the downstream(Cyklon) as backup, which will act as as OPV, in case.

The OPV is built into the second stage end of the Poseiden hose. So if you just used a coupler and added 3' between the first stage end of the hose and the first stage, you still have the OPV and are good to go.

I use separate OPV's on my first stages as I use a full face mask and a gas block on my doubles. With this configuration, when I am breathing off one first stage, the other first stage does not have direct access to a second stage and any increase in IP due to an HP seat leak would need to be able to vent through an OPV. So each first stage has an OPV on it.

I see OPV's for sale for $18-$24.00 but the dealer cost for them from Trident is $3.00 so I would imagine you could get one through your LDS for around $6.00 if they will add it to their next Trident order to save you separate shipping costs - not that it would cost much to ship anyway.

 

[CoalBoy]

DA Aquamaster,

thanks a lot! if it goes for that cheap($6) then 'll try to get one for each of my back gas regs.

complex diving you got there. probly won't go in that direction. no need for FFMs and gas blocks for recreational diving here in the philippines. gas switch can still be done by actually "switching" regs.

wouldn't wanna dive in any water i don't wanna open my mouth into, like sewege ponds or the local river or even the ocean near the cities. hehehe.

 

[Nemrod]

"The construction’s simplicity guarantees high performance, as well as safety regardless of diving conditions.

This gives you a regulator that is easy to breathe at any depth. The Jetstream second stage is equipped with a safety valve in case a high pressure airflow should occur. This safety valve prevents the airstream from flowing out through the mouthpiece straight into your mouth.

The construction will instead, release the flowing air out into the water via the hose. In all cases it is possible to breathe from the second stage.

Tests conducted by the American Navy show that the Jetstream is the only regulator that manages to deliver the correct amount of air at extreme depths and rate of breathing.

Jetstream also won the Swedish Navy´s highest classification, well within the objective breathing test in cold waters.

Jetstream is approved according to the EN250 cold water standard. "

Note their description of the safety valve and it's purpose. Note that this regulator is servo assited and that the upstrsam valve if I remember the one I took apart is on the servo side. Excess pressure will still offseat the main flow valve that is slaved normally to the servo assit upstram valve via a balancing chamber. It has been a while since I dug into one of these models. That is my recollection, if I am wrong or have the models confused, oh well, I don't remember everything entirely photographic anymore. Good luck. N