<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Alan,</div><div><br></div><div>You're right, and I think ABS also has the same cutoff requirement. When I Iooked back at my design notes I saw that I did have a manual cutoff with the AOP. I'd prefer to go with a light on the indicator panel instead of position near the latch. </div><div><br></div><div>I'm familiar with the DW vacuum setup. Haven't done the calcs to see how long I'd have to let the little compressor run. Have to wear ear protectors I suppose. </div><div><br></div><div>Jim </div><div><br></div><div><br><br>Sent from my iPhone</div><div><br>On Dec 11, 2013, at 3:56 PM, Alan James <<a href="mailto:alanlindsayjames@yahoo.com">alanlindsayjames@yahoo.com</a>> wrote:<br><br></div><blockquote type="cite"><div><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:14pt"><div><span>Jim,</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;">the Deep Workers have an external attachment for pulling a </div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;">vacuum pre dive to set the seals. However they are boat launched</div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;">& it
would be more of an issue if there was a slight leak in the hatch seal.</div><div style="font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;">>>><span style="font-family: arial, helvetica; font-size: 16px;"> <span style="color: rgb(156, 0, 92);">However I think I would like to have a way to cap off the AOP if it began to leak</span><span style="color: rgb(68, 0, 98);">.</span> </span></div><div>G.L. Section 9 B, 1.2 .....Pipes which are led through the pressure hull wall</div><div>are to be fitted with two shut off devices, one of which is to be located</div><div>immediately at the hull wall.</div><div> I am interpreting this as meaning that the over-pressure valve requires an </div><div>additional valve, which makes it difficult to use the over-pressure valve to</div><div>fully equalize the
hull.</div><div>Alan</div> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 14pt;"> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 12pt;"> <div dir="ltr"> <hr size="1"> <font size="2" face="Arial"> <b><span style="font-weight:bold;">From:</span></b> "<a href="mailto:jimtoddpsub@aol.com">jimtoddpsub@aol.com</a>" <<a href="mailto:jimtoddpsub@aol.com">jimtoddpsub@aol.com</a>><br> <b><span style="font-weight: bold;">To:</span></b> <a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a> <br> <b><span style="font-weight: bold;">Sent:</span></b> Thursday, December 12, 2013 10:02 AM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] G.L. summary Pressure Hull<br> </font> </div> <div class="y_msg_container"><br><div id="yiv9465989316"><div><font color="black" size="2" face="arial">
</font><div style="color: black; font-family: arial, helvetica; font-size: 10pt;">
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</font><div><font face="Arial, Helvetica, sans-serif" size="3" style="background-color:transparent;">Hi Alec,</font></div>
<div><font size="3"></font> </div>
<div><font size="3">It sounds like GL is setting up standards to idiot-proof operations. The manual OP valve blocking the hatch latch is just for complying with their requirement. I hadn't previously thought of a manual OP valve to go with the AOP. However I think I would like to have a way to cap off the AOP if it began to leak. </font></div>
<div><font size="3"></font> </div>
<div><font size="3">The interlock is for situations such as someone closing the hatch but forgetting to latch it or diving solo with the pilot's hatch closed and a rear hatch open. Meticulously following the checklist prevents such disasters, but people sometimes screw up. If not an interlock I would at least want indicator lights rather than depend on a rear passenger's assurances that all is latched.</font></div>
<div><font size="3"></font> </div>
<div><font size="3">I don't know if I would pull a slight vacuum before every dive or not. Only experience will answer that. I have a couple of very small 12V compressors around to try on a shop dive. I may decide I like one and can find a place to mount it. On the other hand it might be a slagiatt (Seemed Like A Good Idea At The Time) that gets discarded. You've saved me from a couple of my ideas in the past.</font></div>
<div><font size="3"></font> </div>
<div><font size="3">Best regards,</font></div>
<div><font size="3">Jim</font></div>
<div></div>
<div></div>
<div style="color: black; font-family: arial, helvetica; font-size: 10pt;">-----Original Message-----<br clear="none">
From: Smyth, Alec <<a href="mailto:Alec.Smyth@covisint.com">Alec.Smyth@covisint.com</a>><br clear="none">
To: Personal Submersibles General Discussion <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none">
Sent: Wed, Dec 11, 2013 2:21 pm<br clear="none">
Subject: Re: [PSUBS-MAILIST] G.L. summary Pressure Hull<br clear="none">
<br clear="none">
<div class="yiv9465989316yqt8253914868" id="yiv9465989316yqt48494"><div id="yiv9465989316AOLMsgPart_2_27772939-d96a-4e06-86ea-84145073cecc">
<div class="yiv9465989316aolReplacedBody" lang="EN-US">
<div class="yiv9465989316WordSection1">
<div class="yiv9465989316MsoNormal"><span style="font-size:11pt;">Gents, I think we’re seriously over-complicating this one. The automatic overpressure valves typically have a spring loaded stem. Want a manual valve? All you
do is put your finger on the stem and press a little. You would do that if you wanted to open the valve at less than its cracking pressure, or just for a little ventilation when there is no pressure differential.</span></div>
<div class="yiv9465989316MsoNormal"><span style="font-size:11pt;"> </span></div>
<div class="yiv9465989316MsoNormal"><span style="font-size:11pt;">I’m not following the interlock part, because if the valve is automatic then you are always equalized and can’t open the hatch in any other condition. </span></div>
<div class="yiv9465989316MsoNormal"><span style="font-size:11pt;"> </span></div>
<div class="yiv9465989316MsoNormal"><span style="font-size:11pt;">As for installing a compressor just for the purposes of pulling a pre-dive vacuum, in my opinion it has a way too high moving-parts-to-benefit ratio. You can
pull a vacuum at the start of the day, on land or (I wish) on the deck of your support ship. But afloat before every single dive? I’m not aware of anyone doing that. </span></div>
<div class="yiv9465989316MsoNormal"><span style="font-size:11pt;"> </span></div>
<div class="yiv9465989316MsoNormal"><span style="font-size:11pt;">Best,</span></div>
<div class="yiv9465989316MsoNormal"><span style="font-size:11pt;"><br clear="none">
Alec</span></div>
<div class="yiv9465989316MsoNormal"><span style="font-size:11pt;"> </span></div>
<div class="yiv9465989316MsoNormal"><b><span style="font-size:10pt;">From:</span></b><span style="font-size:10pt;"> Personal_Submersibles [<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles-bounces@psubs.org?" target="_blank" href="mailto:personal_submersibles-bounces@psubs.org?">mailto:personal_submersibles-bounces@psubs.org</a>]
<b>On Behalf Of </b><a rel="nofollow" shape="rect" ymailto="mailto:jimtoddpsub@aol.com" target="_blank" href="mailto:jimtoddpsub@aol.com">jimtoddpsub@aol.com</a><br clear="none">
<b>Sent:</b> Wednesday, December 11, 2013 10:20 AM<br clear="none">
<b>To:</b> <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">
<b>Subject:</b> Re: [PSUBS-MAILIST] G.L. summary Pressure Hull</span></div>
<div class="yiv9465989316MsoNormal"> </div>
<div>
<div class="yiv9465989316MsoNormal"><span style="">It seems that the need for sensing could be eliminated (as far as the present question goes) by positioning the handle for the pressure relief valve in such a manner that it would
interfere with releasing the hatch latch unless the relief valve handle was in the open position. In other words, you have to move the handle to out of the way before you can get to the hatch release.
</span><span style="font-size:10pt;"></span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal"><span style="font-size:10pt;"> </span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal"><span style="">Having a manual control handle doesn't preclude the relief valve from being automatic. It just means the manual portion leading to the auto portion was open. It seems like a good
idea for the manual valve to be opened at some reasonable depth prior to surfacing so any overpressure is free to flow to the auto relief. You don't want overpressure to blow the hatch open when you're still two feet below the surface. If the relief system
is entirely manual, you have to wait until surfaced to open the valve unless the overpressure is particularly high.</span><span style="font-size:10pt;"></span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal"><span style="font-size:10pt;"> </span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal"><span style="">Jim</span><span style="font-size:10pt;"></span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal"><span style="font-size:10pt;"> </span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal"><span style="font-size:10pt;"> </span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="margin-bottom:12pt;"><span style="font-size:10pt;">-----Original Message-----<br clear="none">
From: Joe Perkel <<a rel="nofollow" shape="rect" ymailto="mailto:josephperkel@yahoo.com" target="_blank" href="mailto:josephperkel@yahoo.com">josephperkel@yahoo.com</a>><br clear="none">
To: 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>><br clear="none">
Sent: Wed, Dec 11, 2013 8:54 am<br clear="none">
Subject: Re: [PSUBS-MAILIST] G.L. summary Pressure Hull</span></div>
<div id="yiv9465989316AOLMsgPart_2_5be39082-9a7e-426a-8051-31d14bd36d72">
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<div class="yiv9465989316MsoNormal">Alan<br clear="none">
<br clear="none">
No definitive answer but we can postulate that both sensing and actuation are involved.
<br clear="none">
<br clear="none">
On sensing, differential pressure on either side of the hatch is translated to a impulse to actuation.<br clear="none">
<br clear="none">
On actuation, a method of locking out the operator from physically un-dogging the hatch, is the only way to meet the standard as per your O.P.<br clear="none">
<br clear="none">
Joe<a rel="nofollow" shape="rect" target="_blank" href="http://overview.mail.yahoo.com/?.src=iOS"><br clear="none">
<br clear="none">
Sent from Yahoo Mail for iPad</a></div>
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<div class="yiv9465989316MsoNormal"><span style="font-size:10pt;"> </span></div>
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<div align="center" class="yiv9465989316MsoNormal" style="text-align:center;"><span style="font-size:9pt;">
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</div>
<div class="yiv9465989316MsoNormal"><b><span style="font-size:9pt;">From:
</span></b><span style="font-size:9pt;">hank pronk <<a rel="nofollow" shape="rect" ymailto="mailto:hanker_20032000@yahoo.ca" target="_blank" href="mailto:hanker_20032000@yahoo.ca">hanker_20032000@yahoo.ca</a>>;
<br clear="none">
<b>To: </b>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">
<b>Subject: </b>Re: [PSUBS-MAILIST] G.L. summary Pressure Hull <br clear="none">
<b>Sent: </b>Wed, Dec 11, 2013 2:36:26 PM </span></div>
</div>
<div class="yiv9465989316MsoNormal"><span style="font-size:10pt;"> </span></div>
<table class="yiv9465989316MsoNormalTable" border="0" cellspacing="0" cellpadding="0"><tbody><tr><td colspan="1" rowspan="1" valign="top" style="padding:0in;">
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<div class="yiv9465989316MsoNormal" style="background:white;"><span style="">Alan,</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="">Is this equalization from overpressure inside the hull? or external pressure. </span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="">Hank </span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;margin-bottom:12pt;"><span style=""> </span></div>
<div>
<div>
<div id="yiv9465989316yqt07881">
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:10pt;">On Wednesday, December 11, 2013 1:23:21 AM, Alan <<a rel="nofollow" shape="rect" ymailto="mailto:alanlindsayjames@yahoo.com" target="_blank" href="mailto:alanlindsayjames@yahoo.com">alanlindsayjames@yahoo.com</a>> wrote:</span><span style=""></span></div>
</div>
<div>
<div id="yiv9465989316">
<div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="">Can anyone enlighten me on what sought of mechanism</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="">is used that renders the opening of the hatch possible only after</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="">equalisation, as per G.L. Requirements?</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="">Thanks</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="">Alan<br clear="none">
<br clear="none">
Sent from my iPad</span></div>
</div>
<div id="yiv9465989316yqt49514">
<div>
<div class="yiv9465989316MsoNormal" style="background:white;margin-bottom:12pt;"><span style=""><br clear="none">
On 11/12/2013, at 3:01 PM, Alan James <<a rel="nofollow" shape="rect" ymailto="mailto:alanlindsayjames@yahoo.com" target="_blank" href="mailto:alanlindsayjames@yahoo.com">alanlindsayjames@yahoo.com</a>> wrote:</span></div>
</div>
<blockquote style="margin-top:5pt;margin-bottom:5pt;">
<div>
<div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">Hi,</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">I'm not covering much in this section because if I started on construction</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">regulations, I would just be duplicating what was printed.</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">G.L. wants you to have manufacturer certificates for every non structural screw.</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">Any company you contract to do your welding has to have their facilities, personal</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">& supervision approved by G.L..</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">Some points of interest are.... hatches need to be opened from both sides, they need</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">to be able to be secured open, they need to be designed in a way that opening of the</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">hatch is only possible after equalization. Two measures are required to guarantee that</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">the hatches are closed & secured before diving; one measure is to be visibly noticeable.</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">Mechanical measures for stopping a banging of the hatch is required.</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">Any external through hulls are to be protected against damage by appendages or covers.</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">If you are doing calculations on a computer you have to prove that the program is suitable.</span></div>
</div>
<div>
<div class="yiv9465989316MsoNormal" style="background:white;"><span style="font-size:14pt;">Alan</span></div>
</div>
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</blockquote>
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<blockquote style="margin-top:5pt;margin-bottom:5pt;">
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