<html><head></head><body><p dir="ltr">That seems to be the case with most of the rule sets, GL, ABS and ASME PVHO included. PVHO is particularly onerous - you can apply for an interpretation, but your question cannot be phrased as wanting an exception for a particular design variation, but must instead be a general question asking for clarification on an existing rule, if it fails to address a particular embodiment.</p>
<p dir="ltr">In my case, I am trying to design for simultaneous compliance with ABS, PVHO and Canadian vessel construction standards, and it's an exercise in frustration.</p>
<p dir="ltr">Sean<br>
</p>
<br><br><div class="gmail_quote">On March 19, 2016 2:23:54 AM MDT, Alan James via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<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_1458375108602_2792">Thanks for the explanation Sean.</div><div id="yui_3_16_0_1_1458375108602_2874">I had a look at the ram frame strength issue in the G.L. rules, & they don't mention anything</div><div id="yui_3_16_0_1_1458375108602_2873" dir="ltr">specific about their strength.</div><div id="yui_3_16_0_1_1458375108602_2968" dir="ltr">I did have a technical advice contract with G.L., & through correspondence realized that there were some areas that were black & white & some areas that were grey. If it looked OK & you could justify yourself then it would pass. </div><div id="yui_3_16_0_1_1458375108602_3097" dir="ltr">Alan</div><div id="yui_3_16_0_1_1458375108602_3190" dir="ltr"><br /></div><div class="qtdSeparateBR" id="yui_3_16_0_1_1458375108602_2791"><br /><br /></div><div
class="yahoo_quoted" id="yui_3_16_0_1_1458375108602_2796" style="display: block;"> <div id="yui_3_16_0_1_1458375108602_2795" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_1_1458375108602_2794" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_1_1458375108602_2793" dir="ltr"> <font id="yui_3_16_0_1_1458375108602_2798" face="Arial" size="2"> </font><hr size="1" id="yui_3_16_0_1_1458375108602_2797" /><font id="yui_3_16_0_1_1458375108602_2798" face="Arial" size="2"> <b><span style="font-weight:bold;">From:</span></b> Sean T. Stevenson 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> Friday, March 18,
2016 1:23 PM<br /> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] hatch detail<br /> </font> </div> <div class="y_msg_container" id="yui_3_16_0_1_1458375108602_3162"><br /><div id="yiv8955771390"><div id="yui_3_16_0_1_1458375108602_3161"><div id="yui_3_16_0_1_1458375108602_3160" dir="ltr">Sorry Alan, the detail was suppressed when I created the image. It isn't really a third groove, but rather just a bit of relief over most of that middle area so that there is positive clearance all the way around (no metal to metal contact). I can get away with this because the conical bearing area is predominately carrying the load.</div>
<div id="yui_3_16_0_1_1458375108602_3193" dir="ltr">Sean<br clear="none" />
</div>
<br clear="none" /><br clear="none" /><div class="yiv8955771390yqt5656332710" id="yiv8955771390yqtfd61975"><div class="yiv8955771390gmail_quote" id="yui_3_16_0_1_1458375108602_3194">On March 17, 2016 1:42:08 PM MDT, Alan James via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<blockquote class="yiv8955771390gmail_quote" id="yui_3_16_0_1_1458375108602_3200" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204, 204, 204);padding-left:1ex;">
<div id="yui_3_16_0_1_1458375108602_3199" style="color:#000;background-color:#fff;font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"><div id="yiv8955771390"><div id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_5498"><div id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_5497" style="color:#000;background-color:#fff;font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"><div id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3803"><span id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3844">Hi Sean,</span></div><div id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3805"><span id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3804">you are not showing a third grove for the vacuum path!</span></div><div id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3806">If you get a good metal to metal seal either side of the vacuum hole then you</div><div
id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3807">won't be able to monitor any leak or seat th!
e rest
of the o-ring, or is their a</div><div id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3807" dir="ltr">grove in the landing for this.</div><div id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3807" dir="ltr">Cheers Alan</div><div class="yiv8955771390qtdSeparateBR" id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3808"><br clear="none" /><br clear="none" /></div></div></div></div><div id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_5504"> <div id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3813" style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3812" style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3811" dir="ltr"> <font id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3810" face="Arial" size="2"> </font><div class="yiv8955771390qtdSeparateBR"
id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_5503"><br clear="none" /><br clear="none" /></div><div class="yiv8955771390yqt1480981970" id="yiv8955771390yqtfd03698"><hr size="1" id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3809" /> <b><span style="font-weight:bold;">From:</span></b> Sean T. Stevenson via Personal_Submersibles <personal_submersibles@psubs.org><br clear="none" /> <b><span style="font-weight:bold;">To:</span></b> Personal Submersibles General Discussion <personal_submersibles@psubs.org> <br clear="none" /> <b><span style="font-weight:bold;">Sent:</span></b> Thursday, March 17, 2016 5:29 PM<br clear="none" /> <b><span style="font-weight:bold;">Subject:</span></b> [PSUBS-MAILIST] hatch detail<br clear="none" /> </div></div><div class="yiv8955771390yqt1480981970" id="yiv8955771390yqtfd70208"> <div class="yiv8955771390y_msg_container" id="yiv8955771390yui_3_16_0_ym18_1_1458243221435_3884"><br clear="none" />I sketched the double o-ring seal idea on one
of my hat!
ches,
to<br clear="none" />illustrate what I was getting at. Image is attached. The channel<br clear="none" />through the pressure boundary would connect to a vacuum pump and<br clear="none" />pressure transducer.<br clear="none" /><br clear="none" />Sean<br clear="none" /><br clear="none" /><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 class="yiv8955771390yqt1480981970" id="yiv8955771390yqtfd35418"> </div></div><div
class="yiv8955771390yqt1480981970" id="yiv8955771390yqtfd46010"> </div></div></div><div style="margin-top:2.5em;margin-bottom:1em;border-bottom:1px solid #000;"></div><pre class="yiv8955771390k9mail"></pre><hr /><br clear="none" />Personal_Submersibles mailing list<br clear="none" />Personal_Submersibles@psubs.org<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" /></blockquote></div></div></div></div><br /><div class="yqt5656332710" id="yqtfd97928">_______________________________________________<br clear="none" />Personal_Submersibles mailing list<br clear="none" /><a href="mailto:Personal_Submersibles@psubs.org" shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none" /><a id="yui_3_16_0_1_1458375108602_3204"
href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank" shape="rect">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none" /></div><br /><br /></div> </div> </div> </div></div><p style="margin-top: 2.5em; margin-bottom: 1em; border-bottom: 1px solid #000"></p><pre class="k9mail"><hr /><br />Personal_Submersibles mailing list<br />Personal_Submersibles@psubs.org<br /><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br /></pre></blockquote></div></body></html>