[PSUBS-MAILIST] O2 regulator

Fri Jul 18 20:05:02 EDT 2014

Cliff, What are you using for a CO2 sensor?

Thanks Pete

--------------------------------------------
On Thu, 7/17/14, Cliff Redus via Personal_Submersibles <personal_submersibles at psubs.org> wrote:

 Subject: Re: [PSUBS-MAILIST] O2 regulator
 To: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>
 Date: Thursday, July 17, 2014, 8:30 AM

 Hank
 On the R300, I have life support
 module I call the AMOC system (Air monitoring and Oxygen
 Control).  Connected to the box is a 1/4" SS tubing
 with Swagelok fittings connected to a O2 supply from an
 external 2200 psig O2 bottle. I fill this with welding O2
 with a whip.    In the AMOC module is a medical pressure
 reducing regulator (Hudson model 2000).  This regulator 
 reduces the pressure to around 5 psig.  The pressure
 downstream of the regulator is adjustable with a maximum
 rate of 15 SLPM.  The porting on this regulator is two
 1/4" NPT HP ports and one LP port.  Downstream of
 this regulator, I have installed an O2 thermal mass meter/
 controller from Porter. 
  The model number is 201-FSVP.  This controller can be set
 from 0-10 SLPM via an 0-5V analog input signal. Max
 pressure on the O2 controller is 25 psig.  This O2
 controller also sends out at 0-5V analog output signal of
 the O2 SLPM flow rate.
 Both these items were purchased on
 Ebay at a fraction of list.    I have been very happy
 with the performance of these units.  By measuring the O2
 and CO2 percentages in the cabin, I have a PLC that opens
 and closes this controller to keep the cabin O2 % between
 19-22%.  ABS regulations requires that the O2 be held with
 in 18-24%.  The advantage of this system is that it
 automatically accounts for different metabolic consumptions
 rates for O2.  In the AMOC unit, I have a Swagelok needle
 valve in a bypass around this controller so that if both
 main and back up power are lost, the pilot can manually
 adjust the O2 rate
  into the boat.
 The
 second part to controlling the atmosphere in the cabin is
 scrubbing the CO2.  I initially used a axial flow filter
 with SodaSorb HP.  I found that the axial flow filter did
 not work very well with CO2 in the cabin ranging from 0-7000
 ppm.  Part of the problem was the axial filter arrangement
 and part of the problem was the blower was not strong
 enough.  At the 2012 PSUB convention in Vancouver, Alec
 Symth brought the scrubber he was using on Snoopy as a
 show and tell.  His scrubber is an OTS radial filter that
 is used to clean air.  In 2013, I switch to this type of
 scrubber/filer again with SodaSorb HB and the scrubber has
 worked much better.  It consistently keeps the CO2 level
 below 2000 ppm with most of the time it being 1000-1500
 ppm.  ABS rules require that you keep O2 concentration
 below 5000 ppm.  Part of the reason that is works better
  is the radial design which minimizes the pressure drop
 through the Sodasorb and part is that I have switched to a
 stronger blower.
 Long
 answer to short question.

 Cliff

      On Thursday, July 17, 2014 9:27 AM,
 hank pronk via Personal_Submersibles
 <personal_submersibles at psubs.org> wrote:

  Hi All,I need to find a pediatric
 flow meter and regulator for Gamma.  Or is there something
 better?Hank
 _______________________________________________
 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