Re: Compressor/tire pressure equalization?

On 10 Aug, 22:36, DanKMTB <DanK...@xxxxxxxxx> wrote:
On Aug 10, 4:12 pm, "Leo Lichtman" <leo.licht...@xxxxxxx> wrote:

"someone" wrote:  Depends on regulation method.  If there is zero flow it is

of zero
use.  It is regulator dependent.
^^^^^^^^^^^^^^^^^^^^^
I can think of several uses for air pressure at zero flow.  The simplest one
that comes to mind is using air pressure for closing a clamp.  Frank's
remark referred to a hose connected to a tank.  If you insert a regulator,
then the hose pressure at zero flow will be equal along the entire length of
the hose. and will equal the regulator set point.

OK, so I just came back up from the shop where I checked out the setup
more carefully.  There is a lot more restriction in place than I
thought at the station I normally air up at.  To start with, out of
the reg, we have a ½”NPT male hex nipple.  That goes into a ½” NPT 2
way ball valve.  From that is a KQ2L13-37S elbow, ½”NPT to ½” (O.D.,
3/8” I.D.) poly fitting.  From there is 9’ of Poly tubing, making its
way to a KQ2F13-37S female connector, ½” O.D. tubing to ½” NPH
thread.  From there to a bulkhead with a Q.D. that connects to the
coiled air line, which is 20’, 3/8” I.D.

That’s a lot of stuff to restrict flow.  Based on my initial thought
I’d have expected it all to equalize, but after reading this thread I
guess not.  There’s “line drop” to be expected, and all that stuff is
going to cause quite a bit of line drop.

The reg is also usually set to 110PSI.  I can set it to whatever for
testing (under 125, which is it’s max out).  Any guesses or formulas I
could use to approximate what I’ll need the reg @ to get 100PSI into a
bike tire @ the end of the line?  Even an outright guess, if you want
to throw it out there.  I’ll be able to test tomorrow, weather pending
so I bring the road bike.

Here are a couple pics of the setup.

Reg w/ fittings:  http://tinyurl.com/lgccq6

Bulkhead to Q.D. where 20’ 3/8” I.D. air line attaches:  http://tinyurl.com/m68ca3

I have a guess, but since I've been using this setup and have an idea
how close it gets that'd kind of be cheating.  Anyone wants to help me
figure it out mathematically I'm game, otherwise throw out your
guesses and we'll find out tomorrow.

I’d also like to say I’ve learned quite a bit here already, which was
my intention when I started.  Of course I could have just turned up
the reg and used a gauge, but I wanted to understand what was going
on.  Thanks for the help.

115-120psi guessing that the reg needs 1 atmosphere to work and there
is no bleed ff pipe from your regulator so the difference must be in
the line.
.

Relevant Pages

  • Re: Compressor/tire pressure equalization?
    ... It is regulator dependent. ... I can think of several uses for air pressure at zero flow. ... The reg is also usually set to 110PSI. ...
    (rec.bicycles.tech)
  • Re: Compressor/tire pressure equalization?
    ... It is regulator dependent. ... I can think of several uses for air pressure at zero flow. ... remark referred to a hose connected to a tank. ...
    (rec.bicycles.tech)
  • Re: Buying a regulator/newbie question.
    ... steered me directly to the $990 regulator to start with... ... If you're buying a reg, you need to sit down, without a salesman ... Even here in the St-Lawrence I doubt I'll go diving - too freaking cold and there are lots of those for sale, used, as people do it a few times and say, "no more". ...
    (rec.scuba)
  • Re: newbie Q & A - safety devices
    ... Modern pressure sensing computers make all sorts of racket to wake up the ... When Gagnan modified his reg for Cousteau in the mid-1940s, ... As the location of the exhaust valve was ... the only patentable feature of the regulator, ...
    (rec.scuba)
  • Re: Taking the hummm out of a circuit
    ... I only see .1uF at the output of the regulator. ... Try compensating by buffering the output with an elco of say 2200u instead ... For low currents the transistor is closed, reg takes it all ...
    (sci.electronics.basics)