Need help with hardware

I have a device (of my own design) hooked into my pitot-static
system using barbed tee's, breeze clamps and Tygon tubing.
The problem is it is too hard to remove. (And I have to remove
it often since my device is still under development).

What kind of fitting could I put into the line to make it easy
to disconnect? Obviously the end connected to the airplane
would need some kind of shutoff valve, or at least a way to
easily screw in a plug to make it air tight.

As near as I can measure the tubing is 1/4 inch I.D and 3/8 O.D.
I assume this is not the kind of thing I can find at the hardware
store? I looked on-line at Aircraft spruce and other sources of
hardware, but the problem is that there are thousands of parts
with fuzzy (or no) pictures and no explanation of what and how to
use these parts. I guess one needs to be a mechanic to know these
things?

Thanks in advance for any help

~Paul Mennen

AS&S has a quick disconnect for 1/4" ID line, I use them for fuel but you
can use them for air, you need to order one male and one female. QD001 or
QD002 is the p/n, I think. Search for "QUICK DISC" in the online catalog.
They don't have pics, though.

Juan

"Paul Mennen" wrote in message
...
I have a device (of my own design) hooked into my pitot-static
system using barbed tee's, breeze clamps and Tygon tubing.
The problem is it is too hard to remove. (And I have to remove
it often since my device is still under development).

What kind of fitting could I put into the line to make it easy
to disconnect? Obviously the end connected to the airplane
would need some kind of shutoff valve, or at least a way to
easily screw in a plug to make it air tight.

As near as I can measure the tubing is 1/4 inch I.D and 3/8 O.D.
I assume this is not the kind of thing I can find at the hardware
store? I looked on-line at Aircraft spruce and other sources of
hardware, but the problem is that there are thousands of parts
with fuzzy (or no) pictures and no explanation of what and how to
use these parts. I guess one needs to be a mechanic to know these
things?

Thanks in advance for any help

~Paul Mennen

Paul, You're dealing with such tremendous pressures here, all you need
to do is
put a little soap on the barbed fitting & push the line on---it will
conform to the
barbs enough that it won't blow off until you reach 0.5Mach.--leave the
clamps off.

Paul Mennen wrote:

I have a device (of my own design) hooked into my pitot-static
system using barbed tee's, breeze clamps and Tygon tubing.
The problem is it is too hard to remove. (And I have to remove
it often since my device is still under development).

What kind of fitting could I put into the line to make it easy
to disconnect? Obviously the end connected to the airplane
would need some kind of shutoff valve, or at least a way to
easily screw in a plug to make it air tight.

As near as I can measure the tubing is 1/4 inch I.D and 3/8 O.D.
I assume this is not the kind of thing I can find at the hardware
store? I looked on-line at Aircraft spruce and other sources of
hardware, but the problem is that there are thousands of parts
with fuzzy (or no) pictures and no explanation of what and how to
use these parts. I guess one needs to be a mechanic to know these
things?

Thanks in advance for any help

~Paul Mennen

Paul, You're dealing with such tremendous pressures here, all you need
to do is put a little soap on the barbed fitting & push the line on---
it will conform to the barbs enough that it won't blow off until you
reach 0.5Mach.--leave the clamps off.

Actually I already tried that solution, but the clamps are not the
problem. If I push the tube all the way on the fitting it is
amazingly hard to pull the tube off. I can usually do it outside
the airplane, but not lying on my back reaching up under the
instrument panel. I end up just cutting the tubes off, but there
is a limited number of times I can do that before the tubes will
get too short. Perhaps if I don't push the tube on all the way ...
But it would be a fine line. Or perhaps Tygon isn't the right
stuff, and another tubing type would make it easier? Still I
think a fancier fitting might be appropriate.

~Paul

Paul Mennen wrote:
Paul, You're dealing with such tremendous pressures here, all you need
to do is put a little soap on the barbed fitting & push the line on---
it will conform to the barbs enough that it won't blow off until you
reach 0.5Mach.--leave the clamps off.


Actually I already tried that solution, but the clamps are not the
problem. If I push the tube all the way on the fitting it is
amazingly hard to pull the tube off. I can usually do it outside
the airplane, but not lying on my back reaching up under the
instrument panel. I end up just cutting the tubes off, but there
is a limited number of times I can do that before the tubes will
get too short. Perhaps if I don't push the tube on all the way ...
But it would be a fine line. Or perhaps Tygon isn't the right
stuff, and another tubing type would make it easier? Still I
think a fancier fitting might be appropriate.

~Paul



There are a couple of choices.


Parker has some great fittings which allow the connection to be broken
and reinserted with only one hand. They are not very expensive either!
These fittings are used in hydraulic and air applications. (truck brakes)
I've used these for connections in my pitot/static test box. 100% air tight!

Another is to get a set of hose pliers. They are designed to disconnect
hoses from barbed fittings.

Dave

remove the _nospam

On Wed, 27 Aug 2003 14:32:10 GMT, "Paul Mennen"
wrote:

Paul, You're dealing with such tremendous pressures here, all you need
to do is put a little soap on the barbed fitting & push the line on---
it will conform to the barbs enough that it won't blow off until you
reach 0.5Mach.--leave the clamps off.

Actually I already tried that solution, but the clamps are not the
problem. If I push the tube all the way on the fitting it is
amazingly hard to pull the tube off. I can usually do it outside
the airplane, but not lying on my back reaching up under the
instrument panel. I end up just cutting the tubes off, but there
is a limited number of times I can do that before the tubes will
get too short. Perhaps if I don't push the tube on all the way ...
But it would be a fine line. Or perhaps Tygon isn't the right
stuff, and another tubing type would make it easier? Still I
think a fancier fitting might be appropriate.

~Paul


look up pneumatics in the yellow pages and go to the nearest supplier.
they have push lock fittings that you just pull the end of the fitting
back and it releases the hose see what I'm talking about here

http://www.camozzi-usa.com/

Drew Dalgleish
centralia ont
Murphy Rebel C-FYHO

wrote:
On Wed, 27 Aug 2003, Paul Mennen wrote:


I have a device (of my own design) hooked into my pitot-static
system using barbed tee's, breeze clamps and Tygon tubing.
The problem is it is too hard to remove. (And I have to remove
it often since my device is still under development).


Replace the barbed fittings with hose nipples. When I can't find nipples
and have to use barbs, I chuck the barb in a drill and file the barbs
down, leaving the one nearest the end but smoothing off its sharp edge.
The hose will go on & off easily with no damage, just like a nipple.


would need some kind of shutoff valve


Small brass valves for tubing or screw-in fittings are available at any
auto parts store.

-Dan

Paul,

There maybe parker distrubuters in your area.

Here are a few part numbers.
164pmt-6 3/8 Tee Brass I think

362ptc-6 3/8 y-union composite
354ptc-6 3/8 Tee composite

This is out of catalog 3501E "brass fittings and valves"


http://www.parker.com/brassprod/cat/...nect-Trans.pdf

Hope this helps

Dave
Dallas

http://www.smallparts.com/products/d...ons/10033+.cfm



--
Dan D.



..
"Paul Mennen" wrote in message ...
I have a device (of my own design) hooked into my pitot-static
system using barbed tee's, breeze clamps and Tygon tubing.
The problem is it is too hard to remove. (And I have to remove
it often since my device is still under development).

What kind of fitting could I put into the line to make it easy
to disconnect? Obviously the end connected to the airplane
would need some kind of shutoff valve, or at least a way to
easily screw in a plug to make it air tight.

As near as I can measure the tubing is 1/4 inch I.D and 3/8 O.D.
I assume this is not the kind of thing I can find at the hardware
store? I looked on-line at Aircraft spruce and other sources of
hardware, but the problem is that there are thousands of parts
with fuzzy (or no) pictures and no explanation of what and how to
use these parts. I guess one needs to be a mechanic to know these
things?

Thanks in advance for any help

~Paul Mennen

Also, if you want to connect it to a threaded fitting, Swagelok
www.swagelok.com make a good fitting that uses an insert to stop the tube
collapsing as the tubing is compressed with the two olives. The inserts are
available in brass, aluminium, Nylon, Alloy 400/R-405 steel and stainless.
The fittings are also in a range of materials.

The inserts for Tygon or Vinyl tubing are on page 52 of their "Gaugeable
Tube Fittings and Adapter Fittings" paper catalogue.

Hope this helps,
Peter