BOV - Quick Disconnects & Air Flow

Explorer

Rather than QC-4's or QC-6's or CEJN fittings, why not use compatable fittings used with AP valves. When these hoses are disconnected, both the male and female ends are sealed automatically......comments???????

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Drmike

yeh, they are crap


Swagelock QC series are self flushing to minimise water ingress and come so male and female seal when disconnected.

I struggled with crappy APV quick connects for ages before finally giving up and going to Swagelocks QCs.

Biggest issuse I have with the AP ones was they needed near constant maintenance as they crudded up very quickly when connecting disconnecting underwater a lot, as I was doing

When you disconnect an AP QC and its crudded up it can free flow. When that happens at 140m deph you can empty a AL80 real fast - trust me Freeflow on disconnected AP QC male and theres nothing you can do (have to shut down the valve and cant access gas) free flow on Swagelock QC male and you can push the end of the QC to encourage a re-seal.

AP and Cejn QCs are very primative compared to the Swagelock QC series (price alone should tell you that )

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w ripley

Dave:

I took your advice and recontacted Swagelock's regional and local distributors (they've got a great firewall between the public and Tech Services). One said that they would forward my request on to Tech Services at Swagelock, and the other said something along the same lines. I will post whatever data I recieve.

I did get up with Larry Mieczkowsi who is the "Breathing Air" specialist (US) for CEJN. Larry looked at their line and concluded that the only QD that met the parameters (SS, air flow, working pressures, etc.) came with hose barb ends vs threaded ends.

According to Larry, only the QDs with barbed ends come with "double valves," or with one gate in each side of the QD to keep out water when the QD is disconnected under water.

Larry's a great guy and is sending me a double valved prototype that does have 1/4" NPT ends on it to play around with. It is just a prototype, at this point. When it arrives, I'll take a photo or two and post.

Bill

Dave Sutton

Only have a little free time to post, and will reply to your PM in detail later. Don't get wrapped up with double end shutoffs. They are not needed in most of the connection points. Bottom line is "who cares" if a few CC's of water ges thru a second stage regulator, or an add valve? When needed, a simple checkvalve added between the connector and the fitting is all that is needed. On BOV conections, etc., they are irrelevent. Even the double end shutoff QD's pass a bit of water thru as *none* are dry-connect.

The beauty of using CEJN connections is that many divers aleady USE them but simply don't know it. Viking and Poseidon drysuit hoses and drysuit valves. Apeks, Seaquest, Zeagle, and other BC inflatgors use them (the ones with breathing regulators incorporated in them). Ocean Reef full face mask regulator supply hoses use them (and those parts fit on BOV regulators, etc). So a modular system can be constructed using these parts to integrate not only offboard gas connection, but also other optional gas supply paths. The Swagelok stuff is definately more 'aerospace', but is not as flexable. Everything is a tradeoff, so make your analysis and then accept whatever penalty is associated with the benefit.


The CEJN series you want to use is the one used by Poseidon on the Unisuit and by Apeks on their BC inflator/regulator combo, and by Ocean Reef for their FFM connector. I "think" my memory it is a 102 series? Don't take that as data, but this is the standard that gives the 'dive industry standard connector' compatability. Sadly, it is NOT the same as the QD's that are sold by Golem even though they look the same. Hopefully that will change one day.

Dave

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w ripley

I have posted photos of the CEJN Prototype #228 QD with valves and threaded ends on the M&J Vs. CEJN thread on this list.

Still haven't heard back from Swagelock.

Bill

Dave Sutton

See other thread for discussion. Somehow we're talking about one thing in two places.

Short story is that you still have the wrong parts and are over-thinking the entire thing. Trust me, it's a lot simpler than you are making it.


See you on the other thread.


Dave

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"All animals are equal, but some animals are more equal than others"


Professional Small Boy: Never Successfully Cubicled.

w ripley

Dave:

Thanks for the info. Appreciate your comments but am simply following up on a previous post. I had promised to post when the CEJN prototype came in, and did so.

Bill

fireman

they are 221s. You can get check valves from Mcmaster carr for about $5, if you need them.

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