Installation Instructions
Design BF & BFC ENVIRO-SEALtPTFE Packing
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Use these instructions to install ENVIRO-SEAL packing in
valves that have standard packing or when inspecting or
replacing ENVIRO-SEAL packing.
WARNING
Avoid personal injury or property damage
from sudden release of process pressure or
bursting of parts. 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
from both sides of the valve. Drain the process media from both sides of the valve.
2. If a retrofit kit is being installed in place of the original
packing, it may be necessary to remove the old studs from
the valve because they are too short. Check stud length
by installing the packing and the spring pack assembly using the following assembly procedures, and try installing
the packing nuts. If the packing nuts will not start on the
threads of the studs, it will be necessary to install new studs
and nuts from the retrofit kit.
Note
Ensure that the packing box parts are assembled in the correct order . Packing parts
can not function properly if the Belleville
springs or other packing parts are not
stacked correctly.
3. Use the drawing provided to ensure that the packing
parts are assembled in the correct order. Install the
ENVIRO-SEAL packing parts into the packing box.
4. Install the spring pack assembly (key 217), which includes the attached springs, and packing flange (key 201),
on the stem. Install the nuts (key 212) and hand tighten
them.
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.
If you are installing the system in a valve that is still connected to an actuator, remove the actuator from the valve
to provide sufficient space to install the packing assembly.
If a spring-return actuator is used, it is possible that disconnecting the stem connector will allow the spring to force the
actuator to the end of its travel. Be sure the actuator spring
is resting on its travel stop. Refer to the appropriate valve
and actuator instruction manuals to remove the actuator.
Pressures and Temperatures
Maximum to Maintain Leakage of Less Than 500
ppm: Up to maximum pressure drop capabilities of
the Design BF and BFC valves to 450_F (232_C).
1. Carefully remove the old packing parts from the packing
box. The surface condition of the valve stem and the packing box wall is critical in obtaining a good seal. If the valve
stem needs to be replaced, or any other valve part, refer to
the appropriate valve instruction manual for replacement
procedures. Complete all valve maintenance before installing the ENVIRO-SEAL packing system into the bonnet.
This product may be covered by one or more of the following patents (5,129,625; 5,056,757;
5,131,666; 5,230,498; and 5,299,812) or under pending patent applications.
ENVIRO-SEAL is a mark owned by Fisher Controls International, Inc.
eFisher Controls International, Inc. 1994; All Rights Reserved
Note
Lubrication is required for the packing
studs and nuts.
Although it is important to properly lubricate the stud threads and internal nut
threads, it is also important to properly lubricate the contacting face of the nut.
5. You will obtain maximum benefit from your ENVIROSEAL packing system when you tighten the packing flange
nuts and compress the Belleville springs to their ‘‘target
load.’’ The target load is the point where the Belleville
springs are designed for optimum performance, when they
are compressed to 85% of their maximum deflection, or
nearly flat. (Maximum deflection is when the springs are
100% compressed, or completely flat.)
To obtain the target load of 85% compression of maximum
deflection, perform the following:
D Tighten the packing flange nuts alternately and evenly, keeping the packing flange parallel with the valve flange,
until the Belleville springs are compressed 100% (or completely flat). Refer to the instruction manual for ENVIROSEAL packing systems for sliding stem valves if you need
further assistance.
D For PTFE packing, loosen each packing flange nut
1/2 turn (180 degrees rotation).
D300906X012 5/94
Installation Instructions
Design BF & BFC ENVIRO-SEALtPTFE Packing
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The ‘‘target load’’ of 85% compression has now been
reached.
6. Refer to the appropriate valve and actuator instruction
manuals when connecting the valve to the actuator. Under
normal conditions, the packing nuts should not require retightening.
For additional information concerning the installation of this packing kit, please consult the appropriate Fisher Controls product instruction manual.
PACKING RETROFIT PACKING REPAIR STEM SIZE DIAMETER, IN. (mm)
RBFXPKRT012 RBFXPACK012 1/2 (12.7)
PACKING STUD, QTY 2
(KEY 200)
PACKING NUT, QTY 2
(KEY 212)
PACKING FLANGE
(KEY 201)
SPRING PACK ASSEMBLY
(KEY 217)
ANTI-EXTRUSION WASHER
QTY 4
(KEY 214)
PACKING BOX RING
(KEY 211)
GUIDE BUSHING
(KEY 207)
34B3482-A
PACKING SET, QTY 2
(KEY 215)
PACKING SPACER
(KEY 216)
LOWER WIPER
(KEY 218)
Stems and packing box constructions that do not meet Fisher Controls stem finish specifications, dimensional tolerances,
and design specifications, may adversely alter the performance of this packing kit.
While this information is presented in good faith and believed to be accurate,
Fisher Controls does not guarantee satisfactory results from reliance upon such
information. Nothing contained herein is to be construed as a warranty or guar-
antee, express or implied, regarding the performance, merchantability, fitness
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Fisher Controls
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Printed in U.S.A.
or any other matter with respect to the products, nor as a recommendation to
use any product or process in conflict with any patent. Fisher Controls reserves
the right, without notice, to alter or improve the designs or specifications of the
products described herein.
For information, contact Fisher Controls:
Marshalltown, Iowa 50158 USA Sao Paulo 05424 Brazil
Cernay 68700 France Singapore 2158
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