<html><head></head><body><p dir="ltr">Also, I wouldn't use copper for anything other than domestic water or low pressure air, and even then, it isn't an ideal choice for the marine environment. ABS requires a rating of four times the operating pressure. I typically use Swagelok seamless tubing in 316 SS, and there are different diameters available to match your flow requirements, and different wall thicknesses available to match your pressure requirements. I use HP Autoclave tubing for the really high pressure stuff (15,000 - 60,000 psi), which is also 316 SS - of course, PSubs should never need such pressures.</p>
<p dir="ltr">Sean</p>
<br><br><div class="gmail_quote">On December 7, 2016 4:59:02 PM MST, Brian Cox 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="font-family:Arial, sans-serif; font-size:10pt;"><div>I'm routing my lines to use two scuba tanks as my internal ballast. I estimate the total weight if they are both filled with water to be around 42 lbs. (about 570 cu in for each, alum 80's) . What kind of water line does everybody use? I was considering using soft copper but I'm not sure of it's pressure rating. Or maybe that is not such an issue. It could see some pressure using the HP tanks in a closed position, which then could be an issue I guess. But I would most likely just give a little blast of HP air to push the water out. Hmmm, wonder if I should have the option to vent outside the sub if I had some air pressure in the ballast tanks? or I guess I could just simply let it push all the water out and then it would get expelled that way. Are there any specific rules like that for inside ballast
tanks?</div><div> </div><div>Brian</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>