[PSUBS-MAILIST] Gauge for outside viewport?

Mon Sep 21 19:08:01 EDT 2015

Alec, Where are you thinking of mounting the gauges ? Outside one of the conn viewports ? Outside the dome ? Or 2 sets for one each ?

Pete
--------------------------------------------
On Mon, 9/21/15, Alec Smyth via Personal_Submersibles <personal_submersibles at psubs.org> wrote:

 Subject: Re: [PSUBS-MAILIST] Gauge for outside viewport?
 To: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>
 Date: Monday, September 21, 2015, 8:34 AM

 Exactly.
 The valves to blow ballast are outside and operated via
 through-hulls.
 On Mon, Sep 21, 2015 at
 8:57 AM, James Frankland via Personal_Submersibles <personal_submersibles at psubs.org>
 wrote:
 >1) I
 have a bunch of oil filled gauges lying around, but if they
 are left in any position other than with the rubber caps at
 the top, they leak all over the place. The shelf they live
 on is covered with oil, so I'm just not confident they
 will >keep the oil inside in the
 field. Yes, I suppose so.  The ones
 I have drip.  I thought i'd sprung a minor hull leak at
 first... >2) Yes,
 SCUBA tank gauges have a tiny orifice in their hose fittings
 for just that purpose, to prevent a broken instrument from
 emptying your tank too quickly. That is good and I plan to
 use it on the sub as well. However, the problem >still
 persists that SCUBA gauges can only be taken to under 500
 feet. I came across tech diver accounts of gauge issues such
 as the plastic faces buckling and pinning the needle, or the
 whole enclosure imploding at about 400
 >feet.  oh.  Are you not having
 the HP lines inside the sub at all?  Controlling the air
 with a through hull?  
 RegardsJames
 On 21 September 2015 at
 13:20, Alec Smyth via Personal_Submersibles <personal_submersibles at psubs.org>
 wrote:
 Hi James,
 1) I
 have a bunch of oil filled gauges lying around, but if they
 are left in any position other than with the rubber caps at
 the top, they leak all over the place. The shelf they live
 on is covered with oil, so I'm just not confident they
 will keep the oil inside in the field.
 2) Yes, SCUBA tank gauges have a
 tiny orifice in their hose fittings for just that purpose,
 to prevent a broken instrument from emptying your tank too
 quickly. That is good and I plan to use it on the sub as
 well. However, the problem still persists that SCUBA gauges
 can only be taken to under 500 feet. I came across tech
 diver accounts of gauge issues such as the plastic faces
 buckling and pinning the needle, or the whole enclosure
 imploding at about 400 feet. 

 Thanks,
 Alec  

 On Mon, Sep 21, 2015 at
 5:03 AM, James Frankland via Personal_Submersibles <personal_submersibles at psubs.org>
 wrote:
 Hi Alec, I have a
 couple of thoughts.   1.  The
 gauges I have are chemical protected, so they have an oil
 filled diaphragm separating the inlet line from the gauge
 internals.  Then there is a small vent hole at the top of
 the gauge.  You could attach a rubber hose\bladder to
 this vent hole, top it up with glycerine or whatever the
 gauge is filled with and have a fully compensated valve with
 a bladder. 2.  How about using just
 a normal scuba gauge which will probably be perfectly
 fine.  But, just make a small adapter that screws onto the
 gauge and has only a tiny little orifice to allow the input
 air.  That way if the gauge did ever fail, it would only
 bleed out air slowly and you'd have time to blow
 tanks.  If you are using a scuba 1st stage and piping from
 the HP port (I assume your not and are plumbing straight
 into tanks) then the scuba HP already has this small hole
 for the same reason. Also, it would
 be easy enough to test a gauge.   Find somewhere deep
 enough and take a fishing rod and a packed
 lunch! Im fairly sure Emile has
 external gauges on his sub and its a 200m diver.  He could
 maybe advise? Just a thought.
 Kind Regards
 James  
 On 21 September
 2015 at 06:51, Brian Cox via Personal_Submersibles <personal_submersibles at psubs.org>
 wrote:
 Hi Alec,    New sub ? 
 I must have missed that !    do you have any
 details?    BTW, I received that big gage !  It's
 huge !  I hope I can get it in through the hatch !   As
 it is designed for sea water I assume all I have to do is
 plumb it in, will salt water getting into the tubing cause
 any problems?   Brian

 --- personal_submersibles at psubs.org
 wrote:

 From: Alec Smyth via
 Personal_Submersibles <personal_submersibles at psubs.org>
 To: Personal Submersibles General Discussion
 <personal_submersibles at psubs.org>
 Subject: [PSUBS-MAILIST] Gauge for
 outside viewport?
 Date: Sun, 20 Sep
 2015 23:03:02 -0400

 I have an
 interesting thing to think about and wondered if any of the
 PSUBS brain trust might have a suggestion.
 One of the simplifications on my new
 sub is that all HP air lines are external, aside from the
 BIBS (which is normally shut off anyway). Thus, I'm
 looking for a 3,000-4,000 psi gauge to mount outside a
 viewport, like in the Pisces photo that I'll paste
 below. In case my paste doesn't come through, it is the
 one at the top of the following article: http://www.nytimes.com/2015/09/15/science/piloted-deep-sea-research-is-bottoming-out.html?_r=1
 The first thing that came to mind
 was to use a SCUBA submersible pressure gauge, but the
 problem is these are normally 1 atm dry enclosures of
 limited depth rating. There is generally little information
 posted about how deep they'll go, but what I did find
 was mentioned 260 feet for the plastic ones and 490 feet for
 the brass variety. This is a 1,000 foot sub.
 The second idea was to use oil
 filled gauges intended for above-water use. But these
 generally have considerable bubbles in the oil, are not very
 good at keeping the oil inside, and have other hardware not
 intended to live long in sea water.
 Any suggestions would be most
 welcome!

 Thanks,
 Alec 

 --089e0115ebd0a0d2500520391e8b--_______________________________________________
 Personal_Submersibles mailing list
 Personal_Submersibles at psubs.org
 http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

 _______________________________________________

 Personal_Submersibles mailing list

 Personal_Submersibles at psubs.org

 http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

 _______________________________________________

 Personal_Submersibles mailing list

 Personal_Submersibles at psubs.org

 http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

 _______________________________________________

 Personal_Submersibles mailing list

 Personal_Submersibles at psubs.org

 http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

 _______________________________________________

 Personal_Submersibles mailing list

 Personal_Submersibles at psubs.org

 http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

 -----Inline Attachment Follows-----

 _______________________________________________
 Personal_Submersibles mailing list
 Personal_Submersibles at psubs.org
 http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles