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Hi Frank, The Comsub has rubber hydraulic hoses all over it and
they seem OK. However I prefer the new plastic hydraulic hoses that Parker and
Swagelok sell. Parflex and Synflex are the names. You can get stainless
fittings for them and they will never deteriorate. Chs, Hugh From: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of ShellyDalg@aol.com In a message dated 3/10/2010 1:05:31 P.M. Pacific Standard Time,
hc.fulton@gmail.com writes:
Hi Hugh. Good to hear from you. On the hose thing..... Yes, I was originally planning on using a HP hydraulic hose
like used on a back hoe, ( to eliminate using a pipe union ) but as Vance
said, rubber maybe ain't so good. Yes, it's strong enough, but may corrode. If I can't find a deal on Swagelock parts, I'll stay with schedule
40 SS fittings. I'm not too worried about a little weeping down the
road. Adding another hull stop valve right at the thru-hull nipple
before the HP air line taps in is an acceptable redundancy item that's low
cost. My motivation here is to be able to get a pipe wrench on the pipe line
while submerged. Not a likely scenario, but easily accomplished. On the depth thing...... Where is my math screwed up ? Apart from small differences in
salinity, temperature, etc. the calc is pretty straightforward. Alec got me
thinking I have been making a mistake all this time but I just checked it on
Google and the basic idea is right. Pressure = (depth divided by 33)
X 14.7 psi. OK, it's roughly half the depth. ( 112 psi @ 250 ft. ) It's funny, I was checking Google for the formula and got a NASA
site. To determine pressure at depth they use a complicated formula using
weight of water and a bunch of other stuff, of course all in metric terms. No wonder a wrench is $4000...... I did some work for NASA years ago and they seem to go out of
their way to make things complicated. My original contract was to
be 3 weeks and about $45,000. I ended up there 13 months and $1.3 million. Those guys crack me
up. At NASA, I guess if you don't spend it you don't get it next budget cycle. Me, I'm just a simple guy. Frank D.
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