<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div id="yui_3_16_0_ym18_1_1458747458006_3236"><span>Jon,</span></div><div id="yui_3_16_0_ym18_1_1458747458006_3068"><span id="yui_3_16_0_ym18_1_1458747458006_3067">Yes correct, the idea is to evacuate the air from the pesky little voids trapping air. There would be no need worry about air re-entering the motor cavity after removing the motor from the oil filled vacuum chamber because the oil inside the motor is heavier than air. There would be a short clear tube connected to the motor to create a fill spot and high point. </span></div><div id="yui_3_16_0_ym18_1_1458747458006_3068"><span>Hank</span></div> <div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display: block;"> <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"><font size="2" face="Arial"> On Wednesday, March 23, 2016 9:17 AM, Jon Wallace via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br></font></div> <br><br> <div class="y_msg_container"><br clear="none">I assumed Hank was suggesting the vacuum simply as a means of displacing <br clear="none">air from the motor housing to achieve a complete filling of the cavity <br clear="none">with oil. How would you seal the motor in this manner after all the <br clear="none">cavity is filled with oil and you want to remove it from the vacuum <br clear="none">chamber...a one way valve perhaps?<br clear="none"><br clear="none">Jon<br clear="none"><br clear="none"><div class="yqt7941385663" id="yqtfd94480"><br clear="none">On 3/22/2016 8:35 PM, Stephen Fordyce via Personal_Submersibles wrote:<br clear="none">> Hi guys,<br clear="none">> I've got a reasonable working knowledge of vacuum from being involved <br clear="none">> with design and fabrication of vacuum-insulated pipes and vessels for <br clear="none">> cryogenic fluids, and have a couple of comments on this:<br clear="none">><br clear="none">> 1. I'm missing how it will help having vacuum in a pod when you are at <br clear="none">> depth. Ie. there is still a very large pressure on the outside trying <br clear="none">> to get in (in fact, even more than if the inside was at ambient).<br clear="none">> 2. There's a potential benefit from vacuuming the pod before filling <br clear="none">> with oil (ie. pull a vacuum, then release the vacuum with oil) as it <br clear="none">> means there will be no possibility of condensation from any remaining <br clear="none">> air, and oil will fill all the spaces where air might otherwise get <br clear="none">> trapped. Realistically, the amount of moisture you'd save from the <br clear="none">> air would be pretty negligible, possibly the removal of airspace will <br clear="none">> help with preventing water leaks from the outside.<br clear="none">> 3. Vacuuming the pod with oil or water in it may have weird effects. <br clear="none">> Ie. water will boil (creating residue buildup from salt, tannins, or <br clear="none">> whatever else was dissolved in it). Oil will also evaporate/boil, to <br clear="none">> a much lesser extent, but the thin oil typically used <br clear="none">> for compensating will probably evaporate quite significantly under <br clear="none">> vacuum for long periods.<br clear="none">><br clear="none">> Cheers,<br clear="none">> Steve<br clear="none">><br clear="none">><br clear="none"><br clear="none">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none"><a shape="rect" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div><br><br></div> </div> </div> </div></div></body></html>