8 | Baker Hughes
Copyright 2020 Baker Hughes Company. All rights reserved.
The force can be applied with the actuator as follows:
Place the actuator on the valve bonnet (2) by means of the yoke
nut or bolts (Not Shown) and connect the valve plug stem (8) to
the actuator stem.
CAUTION
CAUTION
WARNING
DANGER
During this operation, make sure the plug does not
turn when it is seated. If the plug travel is very small
and there is a large amount of plug stem inside
the actuator, it may be necessary to remove the
yoke nut and lift the actuator so that the plug is not
touching the seat.
Refer to the appropriate instruction manual for the actuator and
each unique accessory.
Tighten the bonnet stud nuts to the appropriate torque value found
in Table 1. Tighten in sequence using at least 5 equal increments
of torque. (See Figure 7 for torque sequence and recommended
torque steps). It is important to ensure that the bonnet and bonnet
flange are tightened down evenly to ensure proper alignment and
fit of the internal components required for smooth valve operation
and performance. In larger sizes ( 12” and larger), it is highly
recommended that two assembly personnel, directly opposed
to one another, perform the torque sequence and assure even
installation; i.e. no tipping or uneven gaps between the bonnet
flange and body.
At each torque step, torque down the bolting with no bushing
installed and check alignment of the stem and packing bore, then
test fit the stem bushing (7) to ensure that plug to cage alignment is
maintained. After tightening, be sure that the bonnet studs protrude
by at least one thread above the nuts. Studs with less than one
thread above the nut are cause for rejection.
Packing Box Assembly
If applicable, slide the guide bushing (7) onto the valve plug stem
(8) and let it drop to the bottom of the packing box.
Assemble the packing box components per the maintenance
instructions in the Packing Box maintenance procedure on
page 5.
Figure 6: Bonnet orientation
Note: Tighten bonnet nuts in five equal steps.
Figure 7: Torque Sequence
