Actuator Mounting; Parts Ordering - Fisher EHD Instruction Manual

EH Valves (NPS 8 through 14)

Actuator Mounting

The following procedure assumes that the valve and
actuator are fully assembled, but with the actuator
removed from the valve. Unless otherwise identified,
the parts involved in making up the actuator-valve
stem connection are shown in figure 3.
CAUTION
Never use a wrench or pliers on the
valve plug stem and never turn the
valve plug stem while the valve plug
assembly is seated. A damaged stem
could cut the packing and allow
leakage. Turning the plug while seated
could damage the seats allowing
leakage at shutoff.
1. Turn the stem locknuts onto the valve stem.
2. Move the valve plug to the closed position.
3. Place the actuator on the bonnet and secure with
the hex nuts (key 26, figure 11). Connect supply
pressure to the actuator.
4. Make sure the actuator stem is fully retracted.
With a properly assembled direct-acting
spring-return actuator, spring compression forces
the actuator stem to the fully retracted position. A
double-acting piston actuator or a reverse-acting
spring-return actuator requires air pressure (or a
side-mounted handwheel) to stroke the actuator
stem to the fully retracted position.
5. Extend the actuator stem a distance equal to the
travel (as specified on the nameplate).
6. Attach both halves of the stem connector, making
sure the connector fully engages both the actuator
threads and valve plug stem threads. Install the cap
screws in the stem connector, but tighten them only
slightly at this time.
7. Stroke the valve to the fully open position. The
travel indicator should show the valve to be wide
open. If it does not, loosen the screws that hold the
travel indicator scale, and shift the scale to the
required position.
8. Stroke the valve to the closed position. The travel
indicator should show the valve to be closed.
9. If travel is not correct, lift the valve plug assembly
(key 3, figure 12 or 13) off its seat approximately 6.4
18
mm (1/4 inch) and screw the valve plug stem into or
out of the stem connector as follows. To lengthen
travel, turn the valve plug stem into the stem
connector slightly. To shorten travel, turn the valve
plug stem out of the stem connector slightly.
(Turning it out too far will limit the stroke.)
10. After adjusting the stem connection so that the
actuator will properly stroke the valve plug assembly,
tighten the cap screws in the stem connector,
tightening the one opposite the anti-rotation groove
first. Then lock the stem locknuts against the stem
connector.

Parts Ordering

Each valve is assigned a serial number, which can
be found on the valve body. This same number also
appears on the actuator nameplate when the valve
is shipped from the factory as part of a control valve
assembly. Refer to the number when contacting your
Emerson Process Management sales office for
technical assistance or when ordering replacement
parts.
When ordering replacement parts, also be sure to
include the 11-character part number for each part
required from the following parts list.
WARNING
Use only genuine Fisher replacement
parts. Components that are not
supplied by Emerson Process
Management should not, under any
circumstances, be used in any Fisher
valve, because they may void your
warranty, might adversely affect the
performance of the valve, and could
cause personal injury and property
damage.
Neither Emerson, Emerson Process
Management, nor any of their affiliated
entities assumes responsibility for the
selection, use, or maintenance of any
product. Responsibility for the
selection, use, and maintenance of any
product remains with the purchaser
and end-user.
Instruction Manual
April 2009
Note