I need some help.  Since you all have been discussing the vacuum in
the tracker tubing, I am adding some of my findings on the subject.
I rebuilt a Standard Duplex double-valve player system.  The primary
valves are not assembled; only the pneumatic stack and secondary valves
and pouch board are assembled for a vacuum test.

Test 1.  Test for valves with pouch board connected.  I set the vacuum
to 10" water gage with all tracker holes to pouches open to atmosphere.

Results: all pneumatics now closed by vacuum.  This indicates the
pouches are opening the inside valve and letting vacuum into the
pneumatics.

Test 2.  I restart the vacuum but this time all the tracker holes are
taped shut.  However, some pneumatics are still closed.  This would
indicate leaky valve or a pouch is getting atmosphere on the tackler
side of pouches.

Now, with all the tracker bar holes taped shut and with the vacuum on,
if you pull away the tape, which opens the tracker holes to atmosphere,
there is a domino effect: each pneumatic will snap closed, very fast.

Also, there is something else I would like to know.  With vacuum still
on and when your use your finger to close the atmosphere on one tracker
hole, some pneumatics slowly closed while others open and close quickly
and some don't do anything.  If I remember I was able to check all
valves this way before I did any work on the valves or pouches.

If I install the primary valve assembly will the bleeds correct this
problems?

Test 3.  Test tracker holes to pouches:  I connected the water gage to
the tracker atmosphere holes on the pouch board and found a vacuum that
varies from 2" to 8"; so, some pouches are leaking.  I applied a
plastic sealer to the holes in the pouch board and sprayed a coat of
silicon lubricant or sealer on the pouches.

I ran Test 2 again with all the tracker holes shut and with the vacuum
on.  If the tape is pulled away which opens the holes to atmosphere there
is little or no domino effect, as if the system locks up.  Again, if
I use a test tube and draw air from one of the holes, it will operate
the pneumatic.

Is there a bleed problem?  Apparently the pouches previously leak enough
to bleed.

The "How Things Work" test:

In order to get a understanding to see how the valves worked, I made
a vacuum test rig from clear Plexiglas plastic sheet which replaced the
pouch board cover.  Now I can see the valves in action.  I have a water
gage attached to the other end.  I am able to access the wood button
and, with a rod, push the valve off the brass seat.

Results: Some valves responded very fast when I jockey the rod; they
have a snap action.  Some stayed off the brass seat.

Since there are no pouches it has been found that some of the valve
stems were bent or the valves need more wobble to align to brass seat.
(I corrected this, now all valves are now holding vacuum in this test.)

Testing the pouches on the pouch board only, no valve chest:

I also used the same test rig and tested the pouch board only.  I get
only about 4" of vacuum but the pouches are inflated.  The tracker
holes are taped shut.  This is normal without the button.

With the vacuum shut off I have a wooden button attached to a valve
stem which is inserted on top of the pouch and pushes the pouch into
the well.  The plastic acts as a valve guide.  I open the tracker hole
to atmosphere and push the button into the pouch well.  I now tape the
tracker hole shut.  If I apply the vacuum and open the tracker hole and
adjust the valve 1/16" clearance from the pouch and let it move about
1/16" to simulate valve travel, the pouch will move up to push the
button and spring back into pouch well.

Some time ago I sent an email to John Tuttle about pouches. In his
reply he mentioned keeping the clearances between the button and pouch
so the pouch will spring back to the well position.  Now I understand
much better what is talking about.

Lee Walker
Franklin, Indiana
tel.: 1-317-441-0504