<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div><span></span></div><div></div><div> FYI, When I first setup life support system for the R300, I tried to implement a bellows add without the bellows by having the PLC monitor cabin pressure with an accurate barometric pressure sensor (700-1400mBar). The ladder logic would trigger a O2 add when the cabin pressure dropped below a low pressure set point. I found that the system did t work very well for my boat as my cabin pressure was not constant enough due to pressure build due to slow leak into the cabin or due to temperature swings. I abandoned using cabin pressure to trigger O2 makeup and went to measuring the O2 concentration. If the O2 concentration drops two percent below normal air concentration, I trigger O2 makeup at 4 times normal
consumption rate until concentration increased to 1% above normal. This approach worked way better for my boat. I am planning on using the same technique in my next boat.<br><br></div><div><br></div> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div dir="ltr"> <div class="hr" style="margin: 5px 0px; padding: 0px; border: 1px solid rgb(204, 204, 204); border-image: none; height: 0px; line-height: 0; font-size: 0px;" contenteditable="false" readonly="true"></div> <font face="Arial" size="2"> <b><span style="font-weight: bold;">From:</span></b> Alan James via Personal_Submersibles <personal_submersibles@psubs.org><br> <b><span style="font-weight: bold;">To:</span></b> Personal Submersibles General Discussion
<personal_submersibles@psubs.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Monday, October 6, 2014 5:19 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] bellows add<br> </font> </div> <div class="y_msg_container"><br><div id="yiv4513126405"><div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px; background-color: rgb(255, 255, 255);"><div id="yiv4513126405yui_3_16_0_1_1412630397936_6323" dir="ltr"><span id="yiv4513126405yui_3_16_0_1_1412630397936_6322">I agree Hank,</span></div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6325" dir="ltr"><span id="yiv4513126405yui_3_16_0_1_1412630397936_6324">I think you should email Phil & warn him:)</span></div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6333" dir="ltr"><span id="yiv4513126405yui_3_16_0_1_1412630397936_6334">I have thought that if there was an
air leak in to the cabin the bellows add system</span></div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6330" dir="ltr"><span id="yiv4513126405yui_3_16_0_1_1412630397936_6329">would stop adding O2. They have a manual system integrated into the bellows add</span></div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6336" dir="ltr"><span id="yiv4513126405yui_3_16_0_1_1412630397936_6335">unit & a continual feed of O2 regardless of the belows. They would have O2 monitors</span></div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6336" dir="ltr"><span id="yiv4513126405yui_3_16_0_1_1412630397936_6368">with set point alarms if the O2 % was too high or low but how they would address an</span></div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6336" dir="ltr"><span id="yiv4513126405yui_3_16_0_1_1412630397936_6408">alarm issue </span>I don't know.</div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6336" dir="ltr">I like Cliff's method of
having a set volume flowing in (as per DW) & O2 addition generated</div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6336" dir="ltr">by O2 measurements opening an O2 solenoid valve via a PLC. This is similar to a</div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6336" dir="ltr">rebreather & James Cameron's system on the Deepsea Challenger.</div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6336" dir="ltr">Don't get me going on the coffee issue. I buy green beans & roast them. Would grow</div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6336" dir="ltr">them if we had the climate. </div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6336" dir="ltr">My side of Auckland had power. Hugh lives on the Dark side.</div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6336" dir="ltr">Alan</div><div id="yiv4513126405yui_3_16_0_1_1412630397936_6336" dir="ltr"><br clear="none"></div><br clear="none"> <div
class="qtdSeparateBR"><br><br></div><div class="yiv4513126405yqt3851123348" id="yiv4513126405yqt67602"><div id="yiv4513126405yui_3_16_0_1_1412630397936_6347" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yiv4513126405yui_3_16_0_1_1412630397936_6346" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yiv4513126405yui_3_16_0_1_1412630397936_6345" dir="ltr"> <div class="hr" style="margin: 5px 0px; padding: 0px; border: 1px solid rgb(204, 204, 204); border-image: none; height: 0px; line-height: 0; font-size: 0px;" contenteditable="false" readonly="true"></div> <font id="yiv4513126405yui_3_16_0_1_1412630397936_6348" face="Arial" size="2"> <b><span style="font-weight: bold;">From:</span></b> hank pronk via Personal_Submersibles <personal_submersibles@psubs.org><br clear="none"> <b><span
style="font-weight: bold;">To:</span></b> personal_submersibles@psubs.org <br clear="none"> <b id="yiv4513126405yui_3_16_0_1_1412630397936_6452"><span id="yiv4513126405yui_3_16_0_1_1412630397936_6451" style="font-weight: bold;">Sent:</span></b> Tuesday, October 7, 2014 10:07 AM<br clear="none"> <b><span style="font-weight: bold;">Subject:</span></b> [PSUBS-MAILIST] bellows add<br clear="none"> </font> </div> <div class="yiv4513126405y_msg_container" id="yiv4513126405yui_3_16_0_1_1412630397936_6355"><br clear="none">I have been pondering the idea of a bellows add system for Gamma. I am not sure how the DW deals with pressure change due to temperature change. When I am diving Gamma the temperature swing is huge causing a big negative pressure inside. A bellows add system would be dumping O2 in like mad. Does the DW have an automatic O2 over ride or an automatic air release to compensate. Does the pilot manually add air to avoid O2
build up.<br clear="none">When I surface after a dive without the scrubber or O2 feeding in, I have to open my hatch vent valve for what seems like forever to equalize the sub to open the hatch. It is getting better with the air temps dropping. I can't wait to go for a dive when it is snowing. <br clear="none">Hank<br clear="none">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a href="mailto:Personal_Submersibles@psubs.org" target="_blank" rel="nofollow" shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none"><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank" rel="nofollow" shape="rect">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"><br clear="none"><br clear="none"></div> </div> </div></div> </div></div></div><br><div class="yqt3851123348"
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