Cashco 521 User Manual

Page 13

IOM-521

As pressure decreases, thru the hole in
the bonnet where the vented plug (12) was
removed, watch for the anti-rotational "stop"
(square or fl at surface of the stem) to appear.

NOTE: This "stop" should not function as
an up travel stop and push up against the
bonnet (2) (metal to metal). A gap of ap-
proximately 1/16" (1-1/2 mm) should exist
between these two surfaces.

NOTE: The purpose of a correct calibration
of the stem stroke is to cause the up travel
to be limited by the actuator travel stop nut.

10. To limit the up travel, rotate the travel stop

nut (52) CW and secure to bottom of attach-
ment hub (4).

NOTE: Secure the actuator stem (6) by the
fl ats when rotating the travel stop nut.

NOTE: "Stroke" length is indicated on the
nameplate (40), and is the distance between
the "C" and "O" marks of the indicator plate
(23).

NOTE: The proper calibration of the actua-
tor / valve unit will occur when at the upper
pressure level of bench setting, the valve
plug (3) will be in the "C" position. At the
lower level of the bench setting, the actua-
tor pressure should be within ±8% of the
lower bench range for the designed stroke
length.

11. Reinstall vented pipe plug (12) using “Fluo-

rolube” grease on threads.

12. Release all pressure from actuator.

NOTES