<div dir="ltr">It would go outside one of the CT viewports. Specifically, the one that looks back toward the stern and is therefore seldom used. The tank pressure is something I normally look at just once before a dive. You want to be able to see it if you want to, but it's not a frequent-use item I would put right in front of the pilot where real estate is most precious.<div><div><br></div><div>So far I still haven't located a liquid filled SPG. The one Stephen suggested is for sale in Germany but I haven't located it here yet.</div><div><br></div><div><br></div><div>Thanks,</div><div><br>Alec</div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Sep 21, 2015 at 7:08 PM, Pete Niedermayr via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Alec, Where are you thinking of mounting the gauges ? Outside one of the conn viewports ? Outside the dome ? Or 2 sets for one each ?<br>
<br>
Pete<br>
--------------------------------------------<br>
On Mon, 9/21/15, Alec Smyth via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br>
<br>
Subject: Re: [PSUBS-MAILIST] Gauge for outside viewport?<br>
<span class=""> To: "Personal Submersibles General Discussion" <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>
</span> Date: Monday, September 21, 2015, 8:34 AM<br>
<div><div class="h5"><br>
Exactly.<br>
The valves to blow ballast are outside and operated via<br>
through-hulls.<br>
On Mon, Sep 21, 2015 at<br>
8:57 AM, James Frankland via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>
wrote:<br>
>1) I<br>
have a bunch of oil filled gauges lying around, but if they<br>
are left in any position other than with the rubber caps at<br>
the top, they leak all over the place. The shelf they live<br>
on is covered with oil, so I'm just not confident they<br>
will >keep the oil inside in the<br>
field. Yes, I suppose so. The ones<br>
I have drip. I thought i'd sprung a minor hull leak at<br>
first... >2) Yes,<br>
SCUBA tank gauges have a tiny orifice in their hose fittings<br>
for just that purpose, to prevent a broken instrument from<br>
emptying your tank too quickly. That is good and I plan to<br>
use it on the sub as well. However, the problem >still<br>
persists that SCUBA gauges can only be taken to under 500<br>
feet. I came across tech diver accounts of gauge issues such<br>
as the plastic faces buckling and pinning the needle, or the<br>
whole enclosure imploding at about 400<br>
>feet. oh. Are you not having<br>
the HP lines inside the sub at all? Controlling the air<br>
with a through hull? <br>
RegardsJames<br>
On 21 September 2015 at<br>
13:20, Alec Smyth via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>
wrote:<br>
Hi James,<br>
1) I<br>
have a bunch of oil filled gauges lying around, but if they<br>
are left in any position other than with the rubber caps at<br>
the top, they leak all over the place. The shelf they live<br>
on is covered with oil, so I'm just not confident they<br>
will keep the oil inside in the field.<br>
2) Yes, SCUBA tank gauges have a<br>
tiny orifice in their hose fittings for just that purpose,<br>
to prevent a broken instrument from emptying your tank too<br>
quickly. That is good and I plan to use it on the sub as<br>
well. However, the problem still persists that SCUBA gauges<br>
can only be taken to under 500 feet. I came across tech<br>
diver accounts of gauge issues such as the plastic faces<br>
buckling and pinning the needle, or the whole enclosure<br>
imploding at about 400 feet. <br>
<br>
Thanks,<br>
Alec <br>
<br>
On Mon, Sep 21, 2015 at<br>
5:03 AM, James Frankland via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>
wrote:<br>
Hi Alec, I have a<br>
couple of thoughts. 1. The<br>
gauges I have are chemical protected, so they have an oil<br>
filled diaphragm separating the inlet line from the gauge<br>
internals. Then there is a small vent hole at the top of<br>
the gauge. You could attach a rubber hose\bladder to<br>
this vent hole, top it up with glycerine or whatever the<br>
gauge is filled with and have a fully compensated valve with<br>
a bladder. 2. How about using just<br>
a normal scuba gauge which will probably be perfectly<br>
fine. But, just make a small adapter that screws onto the<br>
gauge and has only a tiny little orifice to allow the input<br>
air. That way if the gauge did ever fail, it would only<br>
bleed out air slowly and you'd have time to blow<br>
tanks. If you are using a scuba 1st stage and piping from<br>
the HP port (I assume your not and are plumbing straight<br>
into tanks) then the scuba HP already has this small hole<br>
for the same reason. Also, it would<br>
be easy enough to test a gauge. Find somewhere deep<br>
enough and take a fishing rod and a packed<br>
lunch! Im fairly sure Emile has<br>
external gauges on his sub and its a 200m diver. He could<br>
maybe advise? Just a thought.<br>
Kind Regards<br>
James <br>
On 21 September<br>
2015 at 06:51, Brian Cox via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>
wrote:<br>
Hi Alec, New sub ? <br>
I must have missed that ! do you have any<br>
details? BTW, I received that big gage ! It's<br>
huge ! I hope I can get it in through the hatch ! As<br>
it is designed for sea water I assume all I have to do is<br>
plumb it in, will salt water getting into the tubing cause<br>
any problems? Brian<br>
<br>
--- <a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a><br>
wrote:<br>
<br>
From: Alec Smyth via<br>
Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>
To: Personal Submersibles General Discussion<br>
<<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>
Subject: [PSUBS-MAILIST] Gauge for<br>
outside viewport?<br>
Date: Sun, 20 Sep<br>
2015 23:03:02 -0400<br>
<br>
I have an<br>
interesting thing to think about and wondered if any of the<br>
PSUBS brain trust might have a suggestion.<br>
One of the simplifications on my new<br>
sub is that all HP air lines are external, aside from the<br>
BIBS (which is normally shut off anyway). Thus, I'm<br>
looking for a 3,000-4,000 psi gauge to mount outside a<br>
viewport, like in the Pisces photo that I'll paste<br>
below. In case my paste doesn't come through, it is the<br>
one at the top of the following article: <a href="http://www.nytimes.com/2015/09/15/science/piloted-deep-sea-research-is-bottoming-out.html?_r=1" rel="noreferrer" target="_blank">http://www.nytimes.com/2015/09/15/science/piloted-deep-sea-research-is-bottoming-out.html?_r=1</a><br>
The first thing that came to mind<br>
was to use a SCUBA submersible pressure gauge, but the<br>
problem is these are normally 1 atm dry enclosures of<br>
limited depth rating. There is generally little information<br>
posted about how deep they'll go, but what I did find<br>
was mentioned 260 feet for the plastic ones and 490 feet for<br>
the brass variety. This is a 1,000 foot sub.<br>
The second idea was to use oil<br>
filled gauges intended for above-water use. But these<br>
generally have considerable bubbles in the oil, are not very<br>
good at keeping the oil inside, and have other hardware not<br>
intended to live long in sea water.<br>
Any suggestions would be most<br>
welcome!<br>
<br>
<br>
Thanks,<br>
Alec <br>
<br>
<br>
<br>
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