<html><head></head><body><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div></div>
<div>Alan,</div><div>Hmmm, looks like a test is in order. </div><div>Hank</div><div><br></div>
<div id="yahoo_quoted_3511673396" class="yahoo_quoted">
<div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;">
<div>
On Saturday, December 9, 2017, 11:46:13 AM MST, Alan via Personal_Submersibles <personal_submersibles@psubs.org> wrote:
</div>
<div><br></div>
<div><br></div>
<div><div id="yiv8359230449"><div><div>Hank,</div><div id="yiv8359230449AppleMailSignature">Hugh is the expert on this, but....</div><div id="yiv8359230449AppleMailSignature">if the supply pressure is 130psi to the inlet port of the regulator, then if there</div><div id="yiv8359230449AppleMailSignature">was a drop of pressure down stream caused by the piston extending, you</div><div id="yiv8359230449AppleMailSignature">would get pressure at 130psi flowing in until the back pressure in the system </div><div id="yiv8359230449AppleMailSignature">( hose & actuator) reached your set pressure (4psi). It doesn't look</div><div id="yiv8359230449AppleMailSignature">like a simple equation because the 130psi would be flowing in very slowly</div><div id="yiv8359230449AppleMailSignature">initially, as the valve slowly opened. </div><div id="yiv8359230449AppleMailSignature"> Now to the ascent! If you are using a relieving regulator set at 4psi then the</div><div id="yiv8359230449AppleMailSignature">pressure that it relieves at will be set by the strength of the spring in the handle</div><div id="yiv8359230449AppleMailSignature">controlling the relieving valve.</div><div id="yiv8359230449AppleMailSignature">You could change what it is preset at by buying a new spring or maybe grinding</div><div id="yiv8359230449AppleMailSignature">a bit off it. Say it is set at 2psi above your main setting, then the internal pressure</div><div id="yiv8359230449AppleMailSignature">of the regulator would be 6psi above ambient before it started relieving.</div><div id="yiv8359230449AppleMailSignature">The worst case scenario would be ascending from 30ft where the pressure would</div><div id="yiv8359230449AppleMailSignature">double if it wasn't relieved. Any pressure in the hose is going to increase as will</div><div id="yiv8359230449AppleMailSignature">the flow, so not an easy equation. </div><div id="yiv8359230449AppleMailSignature">You might want to guess what internal pressure the actuator can take & be careful</div><div id="yiv8359230449AppleMailSignature">of the wire gland fitting that nothing can blow out.</div><div id="yiv8359230449AppleMailSignature">Cheers Alan <br clear="none"><br clear="none">Sent from my iPad</div><div class="yiv8359230449yqt6027585432" id="yiv8359230449yqt81602"><div><br clear="none">On 10/12/2017, at 1:53 AM, hank pronk 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>> wrote:<br clear="none"><br clear="none"></div><blockquote type="cite"><div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div></div>
<div>Alan, thanks'</div><div>I just googled an air flow chart, and the .125 air hose can supply .5 scfm at 5 psi. So now I have to calculate the volume change in the actuator at my dive rate and see if .5 scfm will supply each actuator. I was not worried about the line supplying the actuator when it was operating. My concern was for the line to keep up while descending. I also thought I might need a relief valve on each actuator for rapid ascents. </div><div>Hank</div><div><br clear="none"></div>
<div class="yiv8359230449yahoo_quoted" id="yiv8359230449yahoo_quoted_2953522424">
<div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;">
<div>
On Saturday, December 9, 2017, 5:25:45 AM MST, hank pronk 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>> wrote:
</div>
<div><br clear="none"></div>
<div><br clear="none"></div>
<div><div id="yiv8359230449"><div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div></div>
<div>Alan,</div><div>I assumed that the air pressure at the out port of the regulator is 4 psi above ambient. My concern is,, will the .125 air line supply air fast enough at 4psi to maintain 4psi above ambient inside the actuator. </div><div>Hank</div><div><br clear="none"></div>
<div class="yiv8359230449yahoo_quoted" id="yiv8359230449yahoo_quoted_3417256645">
<div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;">
<div class="yiv8359230449yqt9574601672" id="yiv8359230449yqt50209"><div>
On Friday, December 8, 2017, 10:01:31 PM MST, Alan 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>> wrote:
</div>
<div><br clear="none"></div>
<div><br clear="none"></div>
<div><div id="yiv8359230449"><div><div>Hank,</div><div id="yiv8359230449AppleMailSignature">you will have the internal space of your actuator to equalise, which</div><div id="yiv8359230449AppleMailSignature">shouldn't be a problem as this will be slowly equalised as you descend.</div><div id="yiv8359230449AppleMailSignature">Then you have the piston going out during manipulator use, & there will be air going</div><div id="yiv8359230449AppleMailSignature">in to fill that void. If you are running either off a 1st stage regulator or a relieving</div><div id="yiv8359230449AppleMailSignature">regulator like Cliff's, the air will be kept at ambient & it will only be that small</div><div id="yiv8359230449AppleMailSignature">flow in to the space the piston has vacated. </div><div id="yiv8359230449AppleMailSignature">You could estimate the internal volume change by using an on line cylinder volume calculator & plugging in the piston diameter & the difference in length it changes </div><div id="yiv8359230449AppleMailSignature">as it protrudes.</div><div id="yiv8359230449AppleMailSignature">If the actuators full stroke takes (as an example) 4 seconds at full speed, &</div><div id="yiv8359230449AppleMailSignature">the volume is 100ml, you could then run air through your intended hose at your supply pressure (130 psi for scuba regulator) in to a small crushed plastic bag, & see if it can</div><div id="yiv8359230449AppleMailSignature">at least fill the bag with 100ml of air in 4 seconds. </div><div id="yiv8359230449AppleMailSignature">Have done similar for rough estimates.</div><div id="yiv8359230449AppleMailSignature">Or just blow through the hose in to a plastic bag ( like lots of people do at Christmas</div><div id="yiv8359230449AppleMailSignature">time) & you might think yep this will do with 130psi behind it.</div><div id="yiv8359230449AppleMailSignature">BTW on A relieving regulator the orifice is pretty small & in Cliff's case it is venting</div><div id="yiv8359230449AppleMailSignature">the internal volume of his 4 thrusters in the last 30ft of ascent.</div><div id="yiv8359230449AppleMailSignature">Cheers Alan</div><div id="yiv8359230449AppleMailSignature"><br clear="none">Sent from my iPad</div><div class="yiv8359230449yqt2247838029" id="yiv8359230449yqt66597"><div><br clear="none">On 9/12/2017, at 4:37 PM, hank pronk 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>> wrote:<br clear="none"><br clear="none"></div><blockquote type="cite"><div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div>Hi All,</div><div>I am new to air compensating so I need to know if the air line size to each of my actuators is critical. To save money I want to recycle the high pressure nylon tubing that is used for hydraulic lines on my hydraulic arm. The nylon air lines are a bit over .125 ID</div><div>thanks'</div><div>Hank </div></div></div></blockquote></div><blockquote type="cite"><div><span>_______________________________________________</span><br clear="none"><span>Personal_Submersibles mailing list</span><br clear="none"><span><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"><span><a rel="nofollow" shape="rect" target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a></span><br clear="none"></div></blockquote></div></div><div class="yiv8359230449yqt2247838029" id="yiv8359230449yqt64733">_______________________________________________<br clear="none">Personal_Submersibles mailing list<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"><a rel="nofollow" shape="rect" target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div></div></div>
</div>
</div></div></div></div><div class="yiv8359230449yqt9574601672" id="yiv8359230449yqt50270">_______________________________________________<br clear="none">Personal_Submersibles mailing list<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"><a rel="nofollow" shape="rect" target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div></div>
</div>
</div></div></div></blockquote></div><blockquote type="cite"><div><span>_______________________________________________</span><br clear="none"><span>Personal_Submersibles mailing list</span><br clear="none"><span><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"><span><a rel="nofollow" shape="rect" target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a></span><br clear="none"></div></blockquote></div></div><div class="yqt6027585432" id="yqt57666">_______________________________________________<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></div>
</div>
</div></div></body></html>