Instruction Manual
D104197X012
NPS 8 CHP Valve
September 2016
12
can be ignored. Scratches or burrs that run across the serrations are not permitted under any conditions, because they will
prevent the gaskets from sealing properly.
1. Install the seat ring gasket (key 17) into the valve body. Install the seat ring (key 6).
2. Install the cage (key 2).
3. Install the seal ring (key 7) onto the valve plug (key 3). Install the anti‐extrusion rings (key 10) onto the valve plug
(key 3). Install the ring with the open side facing the seat end of the valve plug for flow‐down applications (view A of
figure 4). Slide the backup ring (key 8) onto the valve plug. Secure with the retaining ring (key 9).
4. Install the valve plug into the cage.
5. Install the bonnet gasket (key 15) and three cage gaskets (key 16).
6. Install the bonnet over the valve stem and onto the valve body.
Note
The prelubricated hex nuts (key 12) referred to in step 7 can be identified by a black film coating on the nut threads.
The proper bolting procedures in step 7 include ‐‐ but are not limited to ‐‐ ensuring that the bonnet stud threads are clean, and
that the hex nuts are evenly tightened to the specified torque values.
CAUTION
Failure to comply with good bonnet‐to‐body bolting practices and the torque values shown in table 3 may result in damage
to the valve. Cheater bars or slug wrenches should not be used for this procedure. Hot torquing is not recommended.
7. Lubricate the stud threads and the faces of the hex nuts (key 12) with anti‐seize lubricant (not necessary if new
factory prelubricated hex nuts are used). Install the hex nuts, but do not tighten them. Torque the nuts in a
crisscross pattern to no more than 1/4 of the nominal torque value specified in table 3. When all nuts are tightened
to that torque value, increase the torque by 1/4 of the specified nominal torque and repeat the crisscross pattern.
Repeat this procedure until all nuts are tightened to the specified nominal value. Apply the final torque value again
and, if any nut still turns, tighten every nut again.
8. Install new packing and packing box parts per steps 15 and 16 of the Replacing Packing procedure. Be certain to
observe the note given prior to step 15 of that procedure.
9. Mount the actuator by following the procedures in the actuator instruction manual. Check for packing leakage as
the valve is being put into service. Retorque the packing flange nuts as required. See table 2.
Parts Ordering
Each valve body‐bonnet assembly is assigned a serial number which can be found on the valve. 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 serial number when contacting your Emerson Process Management sales office for technical assistance.
When ordering replacement parts, reference the valve serial number to obtain the correct eleven‐character part
number for each part; the following Parts Kit and Parts List is for information only.
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.
