I need to correct a statement I made in an earlier post about the
operation of the Stuart Turner steam pump. In looking at the drawings,
which per former Stuart Turner practice only gives dimensioned details of
all the parts with no clue as to how they go together, I see that the valve
of the Stuart pump is NOT driven 1:1 by the piston rod. Hidden inside the
conventional Stuart steam chest is a shuttle valve arrangement and it is
the shuttle stem which is driven 1:1 by a yoke from the piston rod. In
looking over drawings and text in the same file for several other steam
pumps, the VanBrocklin, Don Young, and a couple of others, all are shuttle
driven from the piston in some way.
Cheers,
Harry
