Maintenance - Fisher A11 Instruction Manual

A11 Valve
prevent shaft leakage. Excessive tightening of
packing will accelerate wear and could produce
higher rotating friction loads on the valve shaft. If
necessary, refer to the Packing Maintenance
section.
2. For ENVIRO-SEAL Packing Systems: These
packing systems will not require this initial
re-adjustment. Refer to the separate ENVIRO-SEAL
Packing System for Rotary Valves Instruction
Manual, Form 5305 for repair and adjustment
procedures.
3. For hazardous atmosphere or oxygen service
valves, read the following Warning, and provide the
bonding strap assembly mentioned below if the
valve is used in an explosive atmosphere.
WARNING
The valve drive shaft is not necessarily
grounded to the pipeline when
installed. Personal injury or property
damage could result, if the process
fluid or the atmosphere around the
valve is flammable, from an explosion
caused by a discharge of static
electricity from the valve components.
If the valve is installed in a hazardous
area, electrically bond the drive shaft
to the valve body.
The packing is composed of all
conductive packing rings (graphite
ribbon packing) or partially conductive
packing rings (carbon-filled PTFE
female adaptor with PTFE V-ring
packing or graphite-composition
packing ring with PTFE/composition
packing) to electrically bond the shaft
to the valve for hazardous area
service. For oxygen service
applications, and hazardous area
service where the standard packing
doesn't provide sufficient
shaft-to-valve body bonding, provide
alternate shaft-to-valve body bonding
according to the following step.
4. Attach the bonding strap assembly (key 131,
figure 4) to the shaft with the clamp (key 130,
figure 4).
8
Note
37A6528-A
A3143-2/IL
VIEW A-A
Figure 4. Optional Shaft-to-Body Bonding Strap
Assembly
5. Connect the other end of the bonding strap
assembly to the valve flange cap screws.
6. For more information, refer to the Packing
Maintenance section below.

Maintenance

Valve parts are subject to normal wear and must be
inspected and replaced as necessary. The
frequency of inspection and replacement depends
upon the severity of service conditions.
WARNING
Avoid personal injury from sudden
release of process pressure. Before
performing any maintenance
operations:
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 on both sides of the
valve. Drain the process media from
both sides of the valve.
D Vent the power actuator loading
pressure.
ACTUATOR
VALVE BODY
A
A