[PSUBS-MAILIST] Electronics contents gauge

Mon Oct 31 06:07:07 EDT 2016

Thanks Steve,
I'll have a think about this one. In my small cabin a failure could be fatal.
With the transmitter's pressure rating it is not likely to burst apart; it would be more 
likely that it leaked because of poor sealing. I doubt this would be major 
though.
Cheers Alan

Sent from my iPad

> On 31/10/2016, at 4:53 pm, Stephen Fordyce via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
> Hi Alan
> Yep, my pressure transmitter is suitable for oxygen (and is ranged 0-400bar).
> 
> A SCUBA reg HP port usually has an orifice built-in to restrict flow in the event of hose failure.  But with even 100bar behind it, the tank will still empty in a matter of minutes - pretty significant.  Having the prolonged restriction of a long skinny tube will help a bit, but a total failure would still put out a lot of gas.
> 
> Cheers,
> Steve
> 
>> On Mon, Oct 31, 2016 at 12:04 PM, Alan James via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> Thanks Emile & Steve.
>> I may combine both suggestions.
>> I am wanting to put my penetrations through a removeable plate
>> a la Deep Worker. It will be behind me in my 1 person submersible;
>> so a pressure transmitter with wires coming from it rather than a gauge
>> looks like the right option.
>> I like the idea of the 1/8th tube. I couldn't find a flow rate anywhere
>> for a 1st stage hp port. May have to flow it in to a plastic bag & get an
>> estimate, to see if a failure would be an issue anyway.
>>    Steve, are those pressure transmitters suitable for oxygen?
>> Cheers Alan
>>  
>> 
>> 
>> From: Stephen Fordyce via Personal_Submersibles <personal_submersibles at psubs.org>
>> To: Personal Submersibles General Discussion <personal_submersibles at psubs.org> 
>> Sent: Monday, October 31, 2016 12:34 PM
>> Subject: Re: [PSUBS-MAILIST] Electronics contents gauge
>> 
>> Hi Alan,
>> I have pressure transmitters (similar to many commonly used in industry) that could probably be adapted for that - see attached photos.  You could replace the end section with a small penetrator/cable gland plate.  It needs a power supply of 6-30VDC and outputs 0.5-4.5V or 4-20mA (both linear).  They are NPT so you'd need an adaptor for the SCUBA HP port - but a 1/4" Swagelok thread will fit.
>> 
>> I imagine you're worried about leaks of HP inside, and maybe cost as well.  Something you may not have thought of is running 1/8" SS tube.  It's soft enough to bend by hand (more like stiff solid-core electrical cable than 1/4" tube) and can be run in a bundle with cables.  Also available in very small inside diameters so flow is greatly restricted.  I've had good success using it for remote gauge lines.
>> 
>> I also have digital HP oxygen pressure gauges if you ever need one of those :).
>> 
>> Shoot me an email at Stephen.fordyce at tfmengineering.com.au if you're interested in one - list price is AU$198.
>> 
>> Cheers,
>> Steve
>> (TFM Engineering Australia)
>> 
>> On Mon, Oct 31, 2016 at 7:19 AM, emile via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> The scuba pressure sensors are wireless. Most scuba divers don’t want it as it is unreliable.
>>  
>> Best would be to screw a industrial pressure sensor (with ¼ “thread or so) into the penetrator plate and attach a HP line on the outside.
>>  
>>  
>> Br, Emile
>>  
>> Van: Personal_Submersibles [mailto:personal_submersibles- bounces at psubs.org] Namens Alan James via Personal_Submersibles
>> Verzonden: zondag 30 oktober 2016 21:02
>> Aan: Personal Submersibles General Discussion
>> Onderwerp: [PSUBS-MAILIST] Electronics contents gauge
>>  
>> Is there a suitable electronic scuba tank contents gauge out there?
>> I am after something that plugs in to the high pressure port of the
>> 1st stage regulator & has wires off it that I can run through a through
>> hull so I can display the tank contents pressure on a screen.
>> Trying to avoid bringing high pressure in to the hull.
>> An alternative may be to run a high pressure line to a through
>> hull & have an electronic pressure gauge threaded in to this from the
>> inside of the hull. However with the second method, I wouldn't have
>> a shut off valve if the pressure gauge failed some how.
>> Alan
>> 
>>  
>> 
>> ______________________________ _________________
>> 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20161031/825db9b0/attachment.html>