Cashco 1078 - Tank Blanketing - Manual (Page 4)

4 IOM-1078
CAUTION
If the valve must be disassembled for any reason,
fi rst make sure all pressure to the blanketing valve is
blocked and any pressure trapped in the valve is vent-
ed safely out. Refer to your company procedure for
any special precautions when handling toxic or other
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.
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. To remove the body internals, simply remove the
tubings (115) and unscrew the pilot body (038) from
the pilot mount (037)(on 1” valve) or from the pilot
connector (047)(on 2” valve). NOTE: Be careful not
to drop internal components. The return spring (025)
could dislodge the spindle (020) as the body and pilot
mount separate.
To Disassemble the Diaphragm Case Assembly:
Relax the compression on spring (007) by fi rst
unscrewing the cap (001). Rotate the jam nut (003)
CCW two rotations and then back out the adjusting
screw (002). Remove nuts (015), lock washers (012),
fl at washers (041) and cap screws (011) from around
the diaphragm case (009). Lift up to remove upper case
assembly, ring gasket (014) and diaphragm assembly.
Remove cap screws (011) and lock washers (012) from
the upper and lower cases to replace gaskets (008).
At re-assembly torque cap screws 13-15 ft-lbs.
To Disassemble Pilot Diaphragm Assembly:
Secure head of center bolt (017) in soft jawed vise.
Rotate nut (015) CCW. Remove nut, fl at washers (033)
and lock washer (012). Lift up to remove upper support
plate (016), gasket (018) and diaphragm (013). Lift up
to remove lower support plate (016) and gasket (018).
To Disassemble the Main Valve Assembly:
1” SIZE VALVES: Remove the four cap screws
(011) and washers (012, 041) holding the mounting
plate (036) to the main body. Carefully lift the pilot
CAUTION
If the piston (107) does not remain in the main body
cavity, it may slowly slide out from the housing. Make
sure the piston does not fall out of the housing while
retracting the housing from the main body.
mount (037) upwards to remove from the main body.
The piston (107) and other internal parts should come
out with the pilot mount. To access the o-rings (105,
106), pull the piston (107) out of the pilot mount and
remove the screw (111) and lock washer (112). The
fl ow plug (109) will come out with a straight pull.
2” SIZE VALVES: Remove the six cap screw (129)
and lock washers (130) holding the piston housing (124)
to the main body. Carefully lift the pilot housing (124)
upwards to remove from the main body. To access
the o-rings (105,106), pull the piston (107) out of the
piston housing or remove it from the main body cavity.
Remove cap screw (011) and lock washer (012). The
fl ow plug (109) will come out with a straight pull.
To access seat ring seal (132), remove cap screws
(011) and lock washers (012) from seat ring (131).
Remove the seat ring from the main body. If the seat
ring is diffi cult to remove, thread two cap screws into
the threaded holes and remove the seat ring by lifting
upwards on the cap screws.
Replace all parts that show signs of damage or excessive
wear. Make sure the material for new parts is suitable
for the service, especially elastomeric components.
If an o-ring needs to be replaced, be sure to use the
correct size and material. Prior to reassembly, make
sure all parts are clean and free of contamination and
seating surface is free of scratches.
Reassemble in reverse order - utilize specifi c
instructions as follows for:
DIAPHRAGM CASE ASSEMBLY: Ensure center
bolt (017) is installed with the threaded end up. Install
one bolt gasket (018) between the center bolt and the
lower support plate (016) as shown on the drawing. An
identical gasket is used between the upper surface of
the sense diaphragm (013) and the bottom side of the
upper support plate. This is to ensure a tight squeeze
CAUTION
DO NOT overtighten threaded connections since dam-
age or breakage may result. Wrap all NPT threads with
TFE tape. Apply anti-seize compound on bolt threads.
Very lightly lubricate all o-rings with a lubricant that is
compatible with the service, sealing surfaces of gas-
kets and diaphragms also.