Fisher EHD Instruction Manual page 7

Instruction Manual
April 2009
personal injury or property damage
caused by uncontrolled movement of
the bonnet, loosen the bonnet by
following the instructions in the next
step.
The following step also provides
additional assurance that the valve
fluid pressure has been relieved.
3. Hex nuts (key 14, figures 12 and 13) attach the
bonnet to the valve body. Loosen these nuts
approximately 3 mm (1/8 inch). Then loosen the
body-to-bonnet gasketed joint by either rocking the
bonnet or prying between the bonnet and valve body.
Work the prying tool around the bonnet until the
bonnet loosens. If no fluid leaks from the joint, proceed
with the bonnet removal in step 5.
WARNING
If the cage sticks to the bonnet,
proceed carefully with bonnet removal
until the cage windows are accessible.
Do not extend hands or arms through
the windows at this point as a sudden
separation of bonnet and cage will
cause personal injury. Use a stick or
other device to thread a rope or sling
through the windows. Use this rigging
to secure the cage to the bonnet or
hoist to prevent damage or injury
should the cage suddenly separate
from the bonnet.
CAUTION
When lifting the bonnet (key 1), be
sure that the valve plug and stem
assembly (keys 3 and 4, figure 12
or 13) remains on the seat ring (key 6,
figure 12 or 13). This avoids damage to
the seating surfaces as a result of the
assembly dropping from the bonnet
after being lifted part way out. The
parts are also easier to handle
separately.
4. Remove the hex nuts (key 14, figure 12 or 13)
and washers (key 29, figure 12 or 13). Carefully lift
Note
EH Valves (NPS 8 through 14)
STEM
CONNECTOR
CAP SCREWS
15A4691-A
A2359-2 / IL
Figure 3. Actuator Mounting
the bonnet off the valve plug stem. If the valve plug
assembly starts to lift with the bonnet, use a brass or
similar hammer to tap the end of the stem and tap it
back down. Set the bonnet on a protective surface to
prevent damage to the bonnet gasket surface.
Use care to avoid damaging gasket
sealing surfaces.
EHD piston rings (key 8) are brittle and
in two pieces. Use care to avoid
damage to the piston rings caused by
dropping or rough handling.
5. Lift the plug assembly (keys 3 and 4, figure 12
or 13) out of the valve body.
6. To remove the cage (key 2, figure 12 or 13), if it
remained in the valve body, install eyebolts or similar
devices into the 1/2 inch 13-UNC tapped holes in the
top of the cage. Using the eyebolts, carefully lift the
cage out of the valve body. Remove the top and
bottom cage gaskets (key 11, figure 12 or 13).
Carefully remove any residual silver or tin from the
gasket surfaces.
7. Cover the opening in the valve body to protect
the gasket surface and to prevent foreign material
from getting into the valve body cavity.
ANTI-ROTATION GROOVE
TRAVEL INDICATOR
STEM CONNECTOR
POINTER
STEM LOCKNUTS
MOUNTING STUDS & NUTS
CAUTION
7