[PSUBS-MAILIST] cable fittings

Mon Jun 15 12:50:04 EDT 2020

Just called Sealcon to confirm how they rate their strain relief fittings
and they base it on line pull so the ones I have won't work. they said that
they also sell a cable clip that attaches to the cable on the pressure side
to keep it from extruding so I might but one of them and do some testing to
see if this will be an option or not.
jRick

On Tue, Jun 9, 2020 at 6:00 AM Alan via Personal_Submersibles <
personal_submersibles at psubs.org> wrote:

> Ian,
>
> https://www.macartney.com/what-we-offer/systems-and-products/connectors/subconn/
> I'm not sure how you get Psub discount. I got some through Jon the
> facilitator / owner
> of the group a long time ago.
> He normally reads the emails & will comment if you have a question.
> There may be an email link to Jon, or more info on the Psub web site.
> He's based in NY, so just a submarine ride away!
> Cheers Alan
>
> On 10/06/2020, at 1:07 AM, Ian Juby via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
> :O  That's them!  Subcon eh? I'll look them up. Psubs gets a discount? How
> does that work?
>
> Ian
>
>
> On Mon, Jun 8, 2020 at 6:46 PM Alan via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
>> Thanks Ian,
>> I have those type of penetrators (below). Psubs gets a discount from
>> subConn
>> that makes them.
>> Would be a bit difficult making them yourself & the bought ones have a
>> securing
>> device so they can't pull apart ( orange thing in photo).
>> I agree that there wouldn't be much call for wet mating them, & that it
>> would just
>> be an opportunity for corrosion.
>> Alan
>>
>> <image1.JPG>
>>
>> On 9/06/2020, at 5:43 AM, Ian Juby via Personal_Submersibles <
>> personal_submersibles at psubs.org> wrote:
>>
>> Hi Rick,
>> I saw your post and wanted to ask if you meant electrical or plumbing
>> through hull connections. So I'm glad you reposted because I haven't been
>> able to follow the thread, nor have I had the time to go back and look
>> stuff up.
>> When I was working R&D on our diver heater system, we used a watertight
>> bulkhead connector for the shot line and remote control. Unfortunately,
>> this was over 20 years ago and I was not the one who actually ordered the
>> connector. So I innernets'd some pictures to try and hopefully find it
>> again because I remember quite well what it looked like, its design and
>> construction. The closest thing I could find was Teledyne Marine's "Wet
>> mate" connectors:
>> http://www.teledynemarine.com/electrical-wet-mate-connectors/
>> I couldn't tell you the price, but I'm sure they weren't cheap. For my
>> ROV project, I'm still in the rough design phase and I keep increasing its
>> depth capabilities. So I'm just going to make my own through-hull
>> connectors, and they will be similar to this design.
>> The through-hull seal is accomplished by a simple and reliable o-ring
>> (which doesn't appear in teledyne's picture). Basically, the rubber
>> connector body is mounted to a brass threaded tube that goes through the
>> bulkhead. The brass threaded tube has a seat for an o-ring which gets
>> compressed by both the nut and external water pressure. Here, I drew a
>> pretty picture:
>>
>> <bulkhead connector.jpg>
>> I just realized I didn't mark the brass tube, but it's the part that goes
>> through the bulkhead.
>> The particular connector we were using only needed to go to like, 300
>> feet. I believe we tested the heater unit to 300 psi and ironically, it was
>> the swagelock fittings inside the unit that leaked - that electrical
>> connector never leaked. We had I think 8 electrical connections passing
>> through that? We could get the identical connector as a straight-through
>> connector, and not an angled connector like my drawing.
>> The pins and sockets were the solid style - in other words there was no
>> splits to allow for expansion or contraction of the sockets or pins. This
>> further added to the waterproof nature as now the wire (a possible leak
>> point) was buried in solid rubber, behind a solid metal socket which itself
>> was buried in solid rubber. Any water wicking along would have to travel
>> 1/2" along the metal/rubber just to get past the socket.
>> The connector body was a hard rubber, both the through-bulkhead block and
>> the male connector. Under high pressures, the water can wick along the
>> inside of the wires (between the copper and the outer insulation) or if you
>> pass the wire through say, silicone rubber, it can wick along the junction
>> of the outside of the wire and the encasing rubber. So the longer that
>> travel distance is, the higher the pressure needs to be to force water
>> through those avenues. That rubber block was only maybe 2 inches left to
>> right in my drawing. I don't remember what pressures or depths it was rated
>> for, but I guarantee you it could take a LOT of pressure. Mechanically
>> (because the bulkhead hole was small) and in keeping watertight. The
>> biggest risk for a leak was if the bulkhead got a scratch where the o-ring
>> seated against it. I have no doubt that connector could have taken
>> hydraulic pressures (thousands of PSI).
>> I did not draw this in my pretty picture, but the head of the brass tube
>> probably had multiple rings inside the rubber, both to get good mechanical
>> locking between the rubber body and the brass body, and to make the
>> greatest distance the water would have to travel to get around from outside
>> to inside the tube, if it were to wick along the junction between brass and
>> rubber. But I'm speculating there because I didn't cut one of those
>> connector$ open to find out. Lest I get fired and stuff for destroying a
>> connector worth hundreds of dollars, you know.  :D Just, when I go to make
>> my own connectors, I'll be making the mounting tube like that, for those
>> reasons. The rubber that made up the connector body filled everything,
>> including right to the bottom of the brass tube.
>> The nice thing about making your own connector as well is that you can
>> make the electrical pins, sockets and wires any size you want to match your
>> electrical current needs.
>>
>> These particular connectors could be plugged and unplugged underwater,
>> but I suspect it would be very difficult to do as it would have to displace
>> water or vacuum from the connector holes. But as you can see, the male pins
>> had insulating rubber for a part of their length to maximize the distance
>> the electricity would have to travel from pin to pin, thus maximizing the
>> electrical resistance from pin to pin as well.
>> Hope that helps,
>> Ian
>>
>>
>> On Mon, Jun 8, 2020 at 12:09 PM Rick Patton via Personal_Submersibles <
>> personal_submersibles at psubs.org> wrote:
>>
>>> I posted the other day about cable threw hull water tight fittings and
>>> only got one response back and was hoping for more feed back as I know most
>>> of you probably don't make your own so for the ones that buy them, is Blue
>>> Globe the only player out there besides sealcon?
>>> Thanks
>>> Rick
>>> _______________________________________________
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>>>
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