4
IOM-1078
CAUTION
If the valve is to be disassembled, first make sure all
pressure to the blanketing valve is blocked and any
pressure trapped inside the valve is vented safely out.
Refer to your company procedure for any special pre-
cautions when handling toxic or hazardous materials.
SECTION VI
VI. MAINTENANCE
The Model 1078 should be periodically actuated and
all sliding surfaces and seals lubricated to ensure
smoothness of operation. The frequency required
depends on the severity of the service conditions. At
least once a year is recommended.
Maintenance pro ce dures hereinafter are based upon
removal of the unit from the vessel where in stalled.
Install the body in a vise with the pilot up wards.
Loosen the tubing fittings and remove all tubing (115).
Refer to the appropriate drawings for disassembly.
Pilot Internals:
NOTE:
The working components and
o-rings within the pilot body may be inspected and
replaced without the need to take apart the diaphragm
case assembly.
To Replace the Pilot Body Internals Only:
NOTE
For 1” size:
Unscrew and remove the lower
portion of the filter canister and filter element from the
filter assembly (202).
Grab the pilot diaphragm case assembly with hands
and rotate the pilot assembly counter clockwise CCW
to remove the pilot body from the pilot mount (on 1”
SIZE); from the pilot connector (on 2” SIZE).
NOTE:
Be careful not to drop
internal
components as the pilot
body is lifted up. Return spring (25) could dislodge the
spindle (20), guide pin (24) and spacer (26) as the pilot
body and pilot mount separate.
Remove o-rings (21,22 and 35). Clean and inspect
trims parts for wear. Replace if worn.
Install new o-ring (35) around the groove adjacent to
the threads on pilot mount (37)(on 1” SIZE); on pilot
connector (47) (on 2” SIZE). Install o-ring (21) around
the outside groove of the spindle (20). Install o-ring (22)
in the internal groove at the lower end of the spindle.
NOTE:
O-RINGS MUST BE ORDERED FROM THE
FACTORY.
Position spacer (26) on top of the pilot mount /
connector. Insert the spring (25) and guide pin (24)
inside the spindle (20) and place these parts into the
Re-install filter element and canister to filter assembly.
Re-connect tubing and fittings.
Rotate closing cap (1) CCW to remove. Rotate jam nut
(3) CCW two rotations and then back out the adjusting
screw (2). Place a set of match marks between the
upper and lower cases. Remove nuts (15), lock
washers (12), flat washers (41) and cap screws (11)
from perimeter of diaphragm case (9). Lift up to remove
upper case assembly. Set spring (7) and spring button
(6) aside. Lift ring gasket (14) and diaphragm assembly
up and remove from lower case (9).
To replace gasket (8) - remove cap screws (11) and
lock washers (12) from the center of the lower case. At
re-assembly torque these cap screws 13-15 ft-lbs.
To Disassemble Pilot Diaphragm Assembly:
Secure hex head of center bolt (17) in soft jawed vise.
Rotate nut (15) CCW and remove nut, lock washer (12)
and flat washers (33). Lift up to remove upper support
plate (16), gasket (18) and diaphragm (13). Lift up to
remove lower support plate (16) and gasket (18). Clean
and inspect parts, replace diaphragm and gasket. At
re-assembly torque nut (15) 4-5 ft-lbs.
To Disassemble the Main Valve Assembly:
For 1” SIZE:
Rotate the four cap screws (11) CCW
and remove washers (12, 41) that hold the mounting
plate (36) to the main body. Carefully lift the pilot mount
(37) upwards to remove from the main body. The piston
WARNING
SPRING UNDER COMPRESSION. Prior to
re mov ing diaphragm case bolts, relieve spring
com pres sion by backing out the adjusting screw.
Failure to do so may result in flying parts that
could cause personal injury.
To Disassemble the Diaphragm Case Assembly:
center of the spacer with the small end of spindle
oriented up.
Lower the pilot body over the top of the spindle.
Ensure that the top of the spindle enters into the small
opening in the center of the body cavity. Press down on
the top of the pilot body and slowly, evenly rotate CW
to engage the threads on the pilot mount or connector
to the pilot body. It is not necessary to use any tool to
ensure a tight seal between the pilot body and the pilot
mount / connection.
