Sounds like Roger Waring might have a bad gasket on the Standard "L"
board that runs between the primaries and secondary valves.  If this
gasket leaks even a little, it will cause the secondary pouches to lift
the valves a little.

A second possibility may be the pouch clearance is not enough.
Another problem I ran into with a standard is the replacement facings
from Player piano Co.  These facings were slightly concave, and they
simply would not seat at low pressure.  There was no way to straighten
them without forcing the collars hard against them.  That, of course,
wouldn't work either.

I did my Standard valves under the watchful eye of Craig Brougher, and
I can hold suction in this stack under my own lung power.  Now if I can
just get it back into the piano!

Andy Taylor
Tempola music rolls