Cashco 31-B - Manual (Page 2)

IOM-31-B 2
10. Regulators are not to be direct buried un der-
ground.
11. For insulated piping systems, recommendation
is to not insulate regulator.
12. Cashco does not recommend fi eld welding on
the body of the regulator. If weld connections
are desired, specify Opt-32, extended plain end
pipe nipples.
SECTION III
2. Model 31-B includes a linkage lever in its mech a-
nism. The linkage lever allows the regulator to
operate fl ow-to-close (FTC) and provides plug
travel multiplication thru the lever length ratio.
3. A complete diaphragm failure will cause the
reg u la tor to fail close.
Figure 1
Recommended Piping Schematic For
Pressure Re duc ing Station
Position 1 Position 2 (Std) Position 3 Position 4
FOR VERTICAL PIPING
FOR HORIZONTAL PIPING
Position 1 Position 3 (Std) Position 2 Position 4
Figure 2
III. PRINCIPLE OF OPERATION
1. Movement of the regulator's internal trim as-
sembly occurs as pressure vari a tions register
on the diaphragm. The registering pressure
is controlled inlet pressure, P
1
, or up stream
pressure. The range spring opposes up wards
movement of the diaphragm due to the P
1
pressure. As inlet pressure drops, the range
spring pushes the diaphragm down, closing the
regulator’s port via the linkage lever travel. As
inlet pressure increases, the diaphragm pushes
up against the range spring and the port opens.