<html><head></head><body><p dir="ltr">Is it always possible to manually actuate the valve if you have a negative differential pressure? I always presumed that a ball or needle valve would be necessary to equalize pressure on either side of a hatch before opening, because such a valve accommodates pressure differences in either direction. With the overpressure valve, in such a situation you need to overcome this difference in addition to the spring preload. That, or I guess you could just bleed some air or oxygen into the cabin.</p>
<p dir="ltr">Sean<br>
</p>
<br><br><div class="gmail_quote">On January 14, 2015 12:36:36 PM MST, 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 dir="ltr" id="yui_3_16_0_1_1421263992272_2764"><span>Brian,</span></div><div dir="ltr"><span>I seem to remember you can manually operate Emile's</span></div><div dir="ltr" id="yui_3_16_0_1_1421263992272_2766"><span id="yui_3_16_0_1_1421263992272_2765">overpressure valve; and it is operating procedure to press</span></div><div dir="ltr" id="yui_3_16_0_1_1421263992272_2768"><span id="yui_3_16_0_1_1421263992272_2767">it to relieve the remaining pressure before opening the hatch.</span></div><div dir="ltr" id="yui_3_16_0_1_1421263992272_2770"><span id="yui_3_16_0_1_1421263992272_2769">If you are looking for an off the shelf solution, make sure</span></div><div dir="ltr" id="yui_3_16_0_1_1421263992272_2771"><span>you can do that.</span></div><div dir="ltr" id="yui_3_16_0_1_1421263992272_2772"><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_1421263992272_2855"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_1_1421263992272_2854"> <div dir="ltr" id="yui_3_16_0_1_1421263992272_2853"> <hr size="1" id="yui_3_16_0_1_1421263992272_2852" /> <font size="2" face="Arial" id="yui_3_16_0_1_1421263992272_2856"> <b><span style="font-weight:bold;">From:</span></b> Brian Cox 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> Thursday, January 15, 2015 6:11 AM<br /> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] Snorkel<br /> </font> </div> <div class="y_msg_container"
id="yui_3_16_0_1_1421263992272_2857"><br /><div id="yiv6875318460"><div id="yui_3_16_0_1_1421263992272_2860"><div style="font-family:Arial, sans-serif;font-size:10pt;" id="yui_3_16_0_1_1421263992272_2859"><div id="yui_3_16_0_1_1421263992272_2858">I don't see where they list the pressure limit on it.</div><div id="yui_3_16_0_1_1421263992272_2861"> </div><div id="yui_3_16_0_1_1421263992272_2862">Brian<br clear="none" /><br clear="none" />--- personal_submersibles@psubs.org wrote:<br clear="none" /><br clear="none" />From: James Frankland via Personal_Submersibles <personal_submersibles@psubs.org><br clear="none" />To: Personal Submersibles General Discussion <personal_submersibles@psubs.org><br clear="none" />Subject: Re: [PSUBS-MAILIST] Snorkel<br clear="none" />Date: Wed, 14 Jan 2015 16:31:56 +0000<br clear="none" /><br clear="none" /></div><div dir="ltr" id="yui_3_16_0_1_1421263992272_2864"><div id="yui_3_16_0_1_1421263992272_2863">what about something like
this? I only just googled it so would need research. Don't quote me on it!</div><div id="yui_3_16_0_1_1421263992272_2865"> </div><div id="yui_3_16_0_1_1421263992272_2867"><a rel="nofollow" shape="rect" target="_blank" href="http://www.haitima.com.tw/valve/check-valve/check-valve-2026.htm" id="yui_3_16_0_1_1421263992272_2866">http://www.haitima.com.tw/valve/check-valve/check-valve-2026.htm</a></div></div><div><br clear="none" /><div>On 14 January 2015 at 15:55, Brian Cox via Personal_Submersibles <span dir="ltr"><<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>></span> wrote:<br clear="none" /><blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204, 204, 204);border-left-width:1px;border-left-style:solid;"><div class="qtdSeparateBR"><br /><br /></div><div class="yiv6875318460yqt6120031758"
id="yiv6875318460yqt28479"><div style="font-family:Arial, sans-serif;font-size:10pt;"><div>Is there an off the shelf over pressure valve that I can get?</div><div> </div><div>Brian<br clear="none" /><br clear="none" />--- <a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a> wrote:<br clear="none" /><br clear="none" />From: James Frankland via Personal_Submersibles <<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><span><br clear="none" />To: Personal Submersibles General Discussion <<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none" /></span>Subject: Re: [PSUBS-MAILIST]
Snorkel<br clear="none" />Date: Wed, 14 Jan 2015 13:58:24 +0000<br clear="none" /><br clear="none" /></div><div><div><div dir="ltr">Yes, my OP valve does not have enough holes. I have a job over the winter to add more or drill existing holes bigger. </div><div><br clear="none" /><div>On 14 January 2015 at 13:04, Emile van Essen via Personal_Submersibles <span dir="ltr"><<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>></span> wrote:<br clear="none" /><blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204, 204, 204);border-left-width:1px;border-left-style:solid;">Mark, All.<br clear="none" />
<br clear="none" />
Mind the area is big enough. The valve in the attachment is designed for a<br clear="none" />
3000 Kg sub. But even then it is to small if you surface too quick in case<br clear="none" />
of massive overpressure.<br clear="none" />
Cracking pressure: 25-75 mBar.<br clear="none" />
<br clear="none" />
<br clear="none" />
Best regards, Emile<br clear="none" />
<br clear="none" />
-----Oorspronkelijk bericht-----<br clear="none" />
Van: Personal_Submersibles [mailto:<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles-bounces@psubs.org" target="_blank" href="mailto:personal_submersibles-bounces@psubs.org">personal_submersibles-bounces@psubs.org</a>]<br clear="none" />
Namens Mark via Personal_Submersibles<br clear="none" />
Verzonden: dinsdag 13 januari 2015 13:12<br clear="none" />
Aan: Personal Submersibles General Discussion<br clear="none" />
Onderwerp: Re: [PSUBS-MAILIST] Snorkel<br clear="none" />
<div><div><br clear="none" />
Since we are discussing over-pressure valves, can you recommend a make and<br clear="none" />
model, or describe its specifications?<br clear="none" />
<br clear="none" />
Regards,<br clear="none" />
<br clear="none" />
Mark...<br clear="none" />
<br clear="none" />
Sent from iPhone.<br clear="none" />
<br clear="none" />
> On Jan 12, 2015, at 7:06 PM, Pete Niedermayr via Personal_Submersibles<br clear="none" />
<<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br clear="none" />
><br clear="none" />
> Scott, I see you have an overpressure valve in place of the snorkel .<br clear="none" />
Whats that on the other side ?<br clear="none" />
><br clear="none" />
> Pete ?<br clear="none" />
> --------------------------------------------<br clear="none" />
> On Mon, 1/12/15, via Personal_Submersibles<br clear="none" />
<<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br clear="none" />
><br clear="none" />
> Subject: Re: [PSUBS-MAILIST] Snorkel<br clear="none" />
> To: "Personal Submersibles General Discussion"<br clear="none" />
<<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none" />
> Date: Monday, January 12, 2015, 5:09 PM<br clear="none" />
><br clear="none" />
> I<br clear="none" />
> would recommend a cabin overpressure valve instead. It is a<br clear="none" />
> mushroom valve. You can see pics on my sub page. Alec<br clear="none" />
> did the same thing.<br clear="none" />
><br clear="none" />
> Thanks,<br clear="none" />
> Scott Waters<br clear="none" />
><br clear="none" />
><br clear="none" />
> -------- Original<br clear="none" />
> Message --------<br clear="none" />
> Subject: [PSUBS-MAILIST] Snorkel<br clear="none" />
> From: Pete Niedermayr via Personal_Submersibles<br clear="none" />
> <<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none" />
> Date: Mon, January 12, 2015 3:58 pm<br clear="none" />
> To: <a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a><br clear="none" />
><br clear="none" />
> I have a set of K 350 plans that I'm using as a<br clear="none" />
> reference for my own design. I'm using the conning tower<br clear="none" />
> plans pretty much as per. The question I do have is. Snorkel<br clear="none" />
> or no snorkel ? On the one hand I can see how it would be<br clear="none" />
> useful have. On the other hand no other design seems to have<br clear="none" />
> one. What are your opinions? Snorkel or no snorkel?<br clear="none" />
><br clear="none" />
> Pete<br clear="none" />
> _______________________________________________<br clear="none" />
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