EZ-C, ET-C, and EWT-C Valves
Instruction Manual
Form 5376
August 2006
4
valve body. However, the control valve assembly
may be installed in any orientation unless limited by
seismic criteria. Other positions may result in uneven
valve plug and cage wear that could result in
improper operation. For mounting assistance,
consult your Emerson Process Management sales
office.
CAUTION
To avoid possible damage to the
packing, do not allow the installed
actuator angle to be so flat as to allow
liquid inside the bonnet to come in
contact with the packing.
Also, if insulation is applied, do not let
the insulation run up the extension
bonnet. This could cause the packing
to freeze and be damaged.
Liquid Service:
The preferred method of mounting
for liquid service is with the actuator vertical above
the valve body. This will allow a vapor layer to form
between the liquid and the packing. If there are
piping constraints, the actuator can be angled
slightly from vertical. However, in no case should the
angle be so flat as to allow liquid inside the bonnet to
come in contact with the packing. For mounting
assistance, consult your Emerson Process
Management sales office.
4. If insulation is applied, make sure it is applied
only to the body/bonnet joint. Do not let the
insulation run up the extension bonnet.
5. Use accepted piping and welding practices when
installing the valve in the line. For flanged valve
bodies, use a suitable gasket between the valve
body and pipeline flanges.
6. If the actuator and valve are shipped separately,
refer to the actuator mounting procedure in the
appropriate actuator instruction manual.
WARNING
Personal injury could result from
packing leakage. Valve packing was
tightened before shipment; however,
the packing might require some
readjustment to meet specific service
conditions.
Valves with ENVIRO-SEAL
R
live-loaded packing will
not require this initial readjustment. See the Fisher
instruction manual titled
ENVIRO-SEAL Packing
System for Sliding-Stem Valves for packing
instructions. If you wish to convert your present
packing arrangement to ENVIRO-SEAL packing,
refer to the retrofit kits listed in the parts kit
sub-section near the end of this manual.
Maintenance
Valve parts are subject to normal wear and must be
inspected and replaced as necessary. Inspection
and maintenance frequency depends on the severity
of service conditions. This section includes
instructions for packing maintenance and trim
maintenance. All maintenance operations may be
performed with the valve in the line.
WARNING
Avoid personal injury or property
damage from sudden release of
process pressure. Before performing
any maintenance operations:
D
Always wear protective gloves,
clothing, and eyewear when
performing any maintenance
operations to avoid personal injury.
D
Disconnect any operating lines
providing air pressure, electric power,
or a control signal to the actuator. Be
sure the actuator cannot suddenly
open or close the valve.
D
Use bypass valves or completely
shut off the process to isolate the
valve from process pressure. Relieve
process pressure from both sides of
the valve. Drain the process media
from both sides of the valve.
D
Vent the pneumatic actuator
loading pressure and relieve any
actuator spring precompression.
D
Use lock-out procedures to be
sure that the above measures stay in
effect while you work on the
equipment.
D
The valve packing box may
contain process fluids that are
pressurized,
even when the valve has
been removed from the pipeline
.
Process fluids may spray out under
pressure when removing the packing
hardware or packing rings, or when
loosening the packing box pipe plug.