M&J Vs. CEJN

Pelagian

Hey Dave

To which of the CEJN fittings are they identical? Most people I've seen are using the 220 series. Are these the ones you're comparing to?

Cheers

Seb

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kiwidiver

The mj male nipple and the cejn nipple.

Dave Sutton

Off the top of my head, it's the 220 series. Look and see and you'll notice that it''s the same series as is used as the standard by Poseidon and Viking on thier drysuit hoses, by Apeks/Zeagle on their inflator/regulator combo, ditto on the Seaquest Air-Source, and by Ocean Reef on their FFM quick connect (a part that threads onto any second stage or BOV). With mass interchangability to other diving hoses used for the same sort of reasons, sticking to it for SESO applications makes sense. When I need a DESO I use a QC-6, but for most of what I build I use CEJN.

CEJN is not the only maker of these fittings, BTW: The 220 series is made by others as well. Hansen, for example, provides the ones used by Seaquest.


Dave

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w ripley

Good luck getting any flow data on any connector, or in-line cut offs for that matter. I've been trying for months, and the best I can get is reassurances from people on this list (whom I trust) that say "this" fitting or "that" fitting will work, because they're tried it or are using it.

When I contacted CEJN Larry Mieczkowski, who handles the diving end, said only the fittings with hose barb ends come with the back-flow valves/gates. However, he did send me a prototype (Prototype #228), which has back-flow valves/gates + has treaded ends, to work with.

I have attached two photographs of the male and female parts. One photo shows the two parts in profile, and the other shows their mating ends. Larry says that all CEJN parts are basically designed to allow unrestricted flow, once the back-flow valves/gates are opened. The inside diameter on the male plug is 4cm/5/16" on the 228. You can do the math for air flow capacity.

However, the female end has a fixed rod/plunger (it is brass in the prototype and should be easy to pick out in the photo) that inserts into the male end to push back the valve/gate on the male end. Its about 1cm in diameter, so I would figure it would have some limiting effect on the actual flow rate of the QC?

Several people on this list have handled Prototype 228 and they all have similar remarks: "It takes two hands to operate, and it's hard to open."

I don't know if all CEJN QDs work like #228, but to open/separate the two pieces of #228 requires holding one piece in one hand and the other in the other hand, and pushing both together (with considerable force) - while moving back the outter unlocking mechanism (a ring) - to take them apart. On the other hand, you simply push the two together and they connect easily - it's more of a spring-action thing. I'm sure the pressure required to push the two pieces together to disconnect the fitting could be reduced if this part were to go into production.

Bill

Attached Images

	CEJN Prototype 003.jpg (104.2 KB, 157 views)
	CEJN Prototype 2 008.jpg (149.1 KB, 152 views)

w ripley

Larry, with CEJN, says they're also working on a Series 341/342 (1/4" NPT or BSP), and will send a sample when it's ready. I'll post photos of that, when it arrives.

Bill

Pelagian

Hey Dave & Bill

That should be all the info I need to get my mods done.

The flowrate information that CEJN has on their website(which isn't working at the moment for some reason) is sufficient for me.

Thank you for your help

Seb

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'Because... I was Inverted!'

Dave Sutton

Gents:

Familarize yourself with a Unisuit drysuit valve and it's hose and you'll familiarize yourself with the correct CEJN parts. You obviously have the wrong bits. The correct ones are exactly like 'slightly larger BC inflator hoses", work the same from a users standpoint (pull the collar one-handed towards the direction the hose will disconnct) and in fact they are found in the "Breathing Air Supply" section of the CEJN catalog (who would have figured that breathing air fittings might be found in the breathing air fittings section of the catalog.... ).

The issue above with the prototype fittings is that you have greatly complicated the issue by asking for DESO fittings. They usually are not needed... use a checkvalve behind a SESO connect and go diving. That's exactly how a drysuit valve works, and they don't leak when you dive with the hose disconnected. Ditto the breathing regulator/inflator combos that use these. The manufacturers of items that use these just stick a checkvalve downstream them if needed, and ignore it if not needed (like at a second stage connection for a BOV). Those parts shown are not compatable with the industry standard drysuit hoses anyhow, so they are a moot point. If you want DESO connections you're 'non-compatable' anyhow so just order any old one from McMaster-Carr, or stick to the defacto diving standard for DESO which is the QC-6. CEJN is "just another manufacturer", so if you get outside the series that connects to "all them other diving hoses" it's a waste of time to deal with them when there are 100's of other QD's available. The defaults for diving are (lower flow OK or desired) = BC quick connect or (DESO Required) QC-6 by Swagelok or Parker.

From an empirical study standpoint, I'll rely on the fact that several OEM's use CEJN connectors (the correct ones) for hose to breathing regulator connection as evidence that the flow rates are adequate, rather than to worry about the math.


Best,

Dave

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Dave Sutton

Poked around a little, and here are the correct fittings:

Series 221 - www.cejn.com



Dave


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"Changes in Lattitudes, Changes in Attitudes, Nothing remains quite the same".... www.nobubblediving.com