Enviro-Sealt Bellows Seal Bonnet; Replacing A Plain Or Extension Bonnet With An Enviro-Seal Bellows Seal Bonnet (Stem/Bellows Assembly) - Emerson Fisher YD Instruction Manual

YD and YS Valves
July 2017
Locate the pilot hole in the valve plug and drill the hole through the plug and stem assembly (determine drill size from
table 4). Drive in the pin to lock the assembly.
6. For ENVIRO‐SEAL bellows seal bonnets, grip the flats of the stem extending out of the top of the bellows shroud
with a soft‐jaw chuck or other type of vise. Screw the valve plug/adaptor assembly onto the valve stem. Tighten as
necessary to align the pin hole in the stem with one of the holes in the adaptor. Secure the adaptor to the stem with
a new pin.
7. Place the upper seat ring (key 7) and upper cage (key 3), respectively, over the plug and stem assembly, being
certain not to scratch any sealing surfaces. Lower this entire assembly into the valve.
8. Place the spiral wound gasket (key 11), shim (key 22), and bonnet gasket (key 9), respectively, over the upper cage.
9. Mount the bonnet onto the valve with the lubricator or pipe plug parallel with the pipeline.
Note
Stud(s) and nut(s) should be installed such that the manufacturer's trademark and material grade marking is visible, allowing easy
comparison to the materials selected and documented in the Emerson/Fisher serial card provided with this product.
WARNING
Personal injury or damage to equipment could occur if improper stud and nut materials or parts are used. Do not operate or
assemble this product with stud(s) and nut(s) that are not approved by Emerson/Fisher engineering and/or listed on the
serial card provided with this product. Use of unapproved materials and parts could lead to stresses exceeding the design
or code limits intended for this particular service. Install studs with the material grade and manufacturer's identification
mark visible. Contact your Emerson representative immediately if a discrepancy between actual parts and approved parts
is suspected.
10. Lubricate the valve stud bolts or cap screws (key 15) and install the nuts (key 16) onto the bolts using good bolting
practices. Tighten the nuts to the recommended bolt torques given in table 5. A pattern similar to that shown in
figure 8 should be followed.
Note
It might be necessary to repeat the bolting pattern several times until the bonnet‐to‐body seal is made, because the tightening of
one nut might loosen an adjacent nut. Repeat the pattern until none of the nuts will turn at the recommended torque.
11. Mount the actuator onto the bonnet and make up the stem connection according to the procedure given in the
appropriate actuator instruction manual.
ENVIRO‐SEAL Bellows Seal Bonnet
Replacing a Plain or Extension Bonnet with an ENVIRO‐SEAL Bellows Seal Bonnet
(Stem/Bellows Assembly)
1. Remove the actuator and bonnet according to steps 1 through 4 of the Disassembly procedure in the Maintenance
section on page 7.
2. With care, remove the valve plug and stem assembly from the valve. If necessary, also lift out the cage.
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Instruction Manual
D100425X012