GX Valve and Actuator
Instruction Manual
Form 5770
June 2006
11
the actuator yoke may cause possible
damage to the valve plug and to the
bellows.
8. Remove the stem adjustor nut (key 27) and
locknut (key 28).
9.
For standard bonnet constructions
, remove
the bonnet and the valve plug/stem assembly and
set on a protective surface.
For extension and bellows bonnet constructions
,
remove only the bonnet (key 4).
For DN150 balanced constructions
, remove the
guide sleeve, bonnet, and valve plug stem
assembly.
10. Remove the valve/yoke gasket
(figures 15, 16, 17, and 18 key 5, figures 19 and 20
key 47) and cover the opening of the valve to protect
the gasket surface and prevent foreign matter from
getting into the valve cavity.
11. Remove the packing follower (key 29) from the
bonnet (key 4).
12. Remove the Belleville spring pack (key 34) and
packing spacer (key 30) from the bonnet (key 4).
Carefully push out the remaining packing box parts
from the bonnet (key 4) using a rounded rod or other
tool which will not scratch the packing box wall.
Clean the packing box and the metal packing box
parts.
CAUTION
Inspect the valve stem, threads and
packing box surfaces for any sharp
edges that might cut the packing.
Scratches or burrs could cause
packing box leakage or damage the
new packing.
13. Inspect the valve stem, threads and packing box
surfaces for any sharp edges that might cut the
packing. Scratches or burrs could cause packing box
leakage or damage the new packing. If the surface
condition cannot be improved by light sanding,
replace the damaged parts.
14. Remove the covering protecting the valve cavity
and install a new valve/yoke gasket
(figures 15, 16, 17, and 18 key 5, figures 19 and 20
key 47) making sure that the gasket seating surfaces
are clean and smooth.
For DN150 balanced constructions,
two gaskets
are required; one between the valve body and guide
sleeve, and the other between the guide sleeve and
bonnet. Ensure the gasket seating surfaces are
clean and smooth for both gaskets.
15. Carefully install the bonnet (key 4) onto the
valve stem.
16. Install the new packing and the metal packing
box parts according to figure 12 for PTFE packing
and according to figure 13 for Graphite ULF packing.
Place a smooth-edged pipe over the valve stem and
gently tap each soft packing part into the packing
box. Apply anti-seize lubricant to the threads and
install the packing follower (key 29).
17. Install the locknut (key 28) and stem adjustor
nut (key 27).
For standard bonnet constructions
, install the
valve plug/bonnet sub assembly into the valve body
(key 1).
18. Mount the actuator onto the valve and install the
body nuts (figures 15, 16, 17, 18 key 7, figures 19
and 20 key 46), but tighten them only finger-tight.
19.
For air-to-open
, connect a separate air supply
to the lower diaphragm casing air supply connection
(as shown in figure 15 or 16) and apply sufficient air
pressure to raise the actuator rod (key 22) to the
travel stop. Proceed to the next step.
For air-to-close
, proceed to the next step.
20.
For standard bonnet constructions
, tighten
the body nuts (key 7) evenly using a cross-tightening
procedure. See table 3 for torque requirements.
For extension and bellows bonnet constructions
,
tighten the bonnet nuts (key 46) evenly using a
cross-tightening procedure. See table 4 for torque
requirements.
21. Tighten the packing follower (key 29) to the
torque specified in table 6.
Alternately, the packing follower can be tightened by
the following method:
a. Tighten the packing follower until the Belleville
springs are compressed 100% (or completely
flat), as detected by a rapid increase in nut
torque.
b.
For DN 15 through DN 100 (1/2 through
4-inch),
loosen the packing follower 60
_
of
rotation.
For DN 150 (6-inch),
loosen the packing follower
180
_
of rotation.
