<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1433884861179_30187"><span>Do you mean if it is crimped Hank?</span></div><div id="yui_3_16_0_1_1433884861179_30186"><span>Or are you saying that just as is it will flatten easily?</span></div><div id="yui_3_16_0_1_1433884861179_30180"><span>Alan</span></div><br> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_1_1433884861179_30191"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_1_1433884861179_30190"> <div dir="ltr" id="yui_3_16_0_1_1433884861179_30189"> <hr size="1" id="yui_3_16_0_1_1433884861179_30188"> <font size="2" face="Arial" id="yui_3_16_0_1_1433884861179_30192"> <b><span style="font-weight:bold;">From:</span></b> hank pronk 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> Wednesday, June 10, 2015 11:27 AM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] Dive report: Snoopy at Seneca<br> </font> </div> <div class="y_msg_container" id="yui_3_16_0_1_1433884861179_30193"><br><br clear="none">Alan,<br clear="none">I think it will flatten under water right away because it is not round and has little strength to keep it round.<br clear="none">Hank--------------------------------------------<br clear="none">On Tue, 6/9/15, Alan James via Personal_Submersibles <<a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br clear="none"><br clear="none"> Subject: Re: [PSUBS-MAILIST] Dive report: Snoopy at Seneca<br clear="none"> To: "Personal Submersibles General Discussion" <<a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none"> Received: Tuesday, June 9, 2015, 7:15 PM<br clear="none"> <br clear="none"> Hi<br clear="none"> Alec,that one<br clear="none"> is also showing 40psi.This is a<br clear="none"> Sean type problem.I guess<br clear="none"> it's a bit like snapping a match stick. Anyone can do<br clear="none"> it, but try breaking it bycrushing<br clear="none"> it from end to end. In this case you can squeeze the tube<br clear="none"> & bend it but try crushing<br clear="none"> it cross sectionally with even pressure all<br clear="none"> around.A<br clear="none"> solution may be to just squeeze up a section of the hose<br clear="none"> with a hose crimpso that a<br clear="none"> point of weakness is created for the water pressure to<br clear="none"> continue crushing thetube from<br clear="none"> there along it's length.Alan<br clear="none"> <br clear="none"> From: Alec Smyth via<br clear="none"> Personal_Submersibles<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"> <br clear="none"> To: Personal<br clear="none"> Submersibles General Discussion<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"> <br clear="none"> Sent:<br clear="none"> Wednesday, June 10, 2015 10:55 AM<br clear="none"> Subject: Re:<br clear="none"> [PSUBS-MAILIST] Dive report: Snoopy at Seneca<br clear="none"> <br clear="none"> Wow. If<br clear="none"> there is no mistake that is really counter intuitive,<br clear="none"> because the hose feels super pliable in your fingers -<br clear="none"> almost like those yellowish rubber lab hoses if you know<br clear="none"> what I mean. The size I'm using is half the wall<br clear="none"> thickness of what you calculated with, if that makes a<br clear="none"> difference. It's 1/4" ID X 3/8" OD X<br clear="none"> 1/16" thickness.<br clear="none"> Alec<br clear="none"> On Tue,<br clear="none"> Jun 9, 2015 at 6:46 PM, Alan James via Personal_Submersibles<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"> wrote:<br clear="none"> <br clear="none"> <br clear="none"> Alec,I had a<br clear="none"> look at the specs on that link. Thanks.The<br clear="none"> 3/8" ID x 5/8" OD X 1/8" tube is rated for<br clear="none"> 40psi internal pressure.As this<br clear="none"> is for fuel there could be a safety margin of 4x, so 160 psi<br clear="none"> burst pressure.I ran a<br clear="none"> couple of plastics I have in my pressure program through<br clear="none"> internal and thenexternal<br clear="none"> pressure, & the maximum external pressure was 2/3rds the<br clear="none"> internal in both cases.This<br clear="none"> could mean that it would take 106 psi before the hose would<br clear="none"> equalize significantly.The<br clear="none"> diameter would maybe shrink a bit before<br clear="none"> collapsing.Cheers<br clear="none"> Alan<br clear="none"> <br clear="none"> <br clear="none"> From: Alec Smyth via<br clear="none"> Personal_Submersibles <<a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none"> To: Personal<br clear="none"> Submersibles General Discussion <<a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none"> <br clear="none"> Sent: Wednesday, June<br clear="none"> 10, 2015 10:11 AM<br clear="none"> Subject: Re:<br clear="none"> [PSUBS-MAILIST] Dive report: Snoopy at Seneca<br clear="none"> <br clear="none"> The stuff<br clear="none"> I'm using is really flexible, and has a wall thickness<br clear="none"> of only 1/16". I'm having trouble imagining that<br clear="none"> the seal could offer less resistance than this, it's<br clear="none"> very soft. See McMaster item #5552K25.<br clear="none"> Best,<br clear="none"> Alec<br clear="none"> On Tue, Jun 9, 2015 at 5:29 PM, Alan James<br clear="none"> via Personal_Submersibles <<a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none"> wrote:<br clear="none"> <br clear="none"> <br clear="none"> Does anyone (Sean)<br clear="none"> have the material specifications in theirpressure programs for the soft pvc that we<br clear="none"> would be using inour<br clear="none"> flexible compensation hoses?The nearest I had was nylon, & that had<br clear="none"> a crush depth of 8,000ftfor a 1 meter long tube, 10mm diameter &<br clear="none"> 2mm wall thickness.I was<br clear="none"> thinking of using oil filled light housings with the<br clear="none"> wiringrunning through<br clear="none"> flexible hose as compensation, but are having second<br clear="none"> thoughts.Alan<br clear="none"> <br clear="none"> From: Sean T.<br clear="none"> Stevenson via Personal_Submersibles <<a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none"> To: Personal<br clear="none"> Submersibles General Discussion <<a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none"> <br clear="none"> Sent: Wednesday, June<br clear="none"> 10, 2015 6:11 AM<br clear="none"> Subject: Re:<br clear="none"> [PSUBS-MAILIST] Dive report: Snoopy at Seneca<br clear="none"> <br clear="none"> I have always<br clear="none"> been a fan of oil compensation at higher than ambient<br clear="none"> pressure, for a variety of reasons. The only real downside<br clear="none"> is the environmental impact of potentially losing oil to the<br clear="none"> surrounding water in the event of a leak, but that impact<br clear="none"> can be mitigated with oil selection. Positive pressure<br clear="none"> allows you to compensate for volumetric changes in your<br clear="none"> compensated volumes due to the exterior pressure, as well as<br clear="none"> for thermal expansion of the oil, and if you have any<br clear="none"> leakage at all, you leak oil out, rather than water in,<br clear="none"> which can be an expensive lesson. Additionally, if you<br clear="none"> provide the bias with something like a spring loaded<br clear="none"> cylinder or elastomeric bladder, you can instrument its<br clear="none"> displacement for accurate monitoring of demanded<br clear="none"> compensation volume, and potentially detect leaks well in<br clear="none"> advance of when they actually become a problem. <br clear="none"> Ambient-only compensation has the disadvantage of not<br clear="none"> compensating for boundary-layer viscosity effects on<br clear="none"> rotating shafts,!<br clear="none"> density<br clear="none"> differences (gravity induced exchange and/or centripetally<br clear="none"> accelerated fluid) and other small but cumulative effects<br clear="none"> that can contribute to water ingress. <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"> <br clear="none"> <br clear="none"> <br clear="none"> <br clear="none"> _______________________________________________<br clear="none"> <br clear="none"> Personal_Submersibles mailing list<br clear="none"> <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"> <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"> <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"> <br clear="none"> <br clear="none"> <br clear="none"> <br clear="none"> _______________________________________________<br clear="none"> <br clear="none"> Personal_Submersibles mailing list<br clear="none"> <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"> <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"> <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"> <br clear="none"> <br clear="none"> <br clear="none"> <br clear="none"> -----Inline Attachment Follows-----<div class="qtdSeparateBR"><br><br></div><div class="yqt5504448226" id="yqtfd26036"><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"> <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></div><br><br></div> </div> </div> </div></body></html>