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22
Instruction Manual
4.4.3 Refill Valve Assembly
(see Figure 8)
.
The only required periodic maintenance for the
refill valve assembly is the suggested annual
replacement of the oil strainer (see above “Oil
Strainer Replacement” section). Clean hydraulic
oil is critical for proper operation. Field servicing
of the valve assembly is limited to inspection and
cleaning only. Repairs of this critical component
should only be carried out by an authorized
Milton Roy repair facility.
The valve is designed to be easily removed through
the bottom of the pump without having to remove
the displacement chamber. The following steps
describe the procedure for removal of the valve
from the displacement chamber
(Figure 8)
:
A. Disassembly
1. Drain oil from the pump housing as described
in the above “Oil Replacement” section.
2. Unscrew the valve body (660) from the
displacement chamber (600).
3. Clean any debris from the valve cavity in the
displacement chamber.
4. Discard O-rings (720, 730).
Note:
When reinstalling the valve assembly, be sure
to install new O-rings (720, 730).
B. Reassembly
1. Install new O-rings (720, 730) and coat rings
with O-ring grease.
2. Screw valve assembly back into displacement
chamber until it reaches mechanical stop.
3. Make sure the strainer (670) is installed and
strainer plug (650) is tight. Valve is now ready for
service. Refill pump casing with recommended
oil as described in the “Oil Replacement”
section.
4.4.4 Diaphragm Replacement
MILROYAL
®
G liquid ends are designed to
provide reliable service under normal operating
circumstances and should not require replacement
of the diaphragm. However, in the unlikely event
of a failure, the diaphragm can be replaced by the
following the procedure:
A. Removal of Diaphragm
(Figures 7 & 8)
:
BEFORE BEGINNING DISASSEMBLY
PROCEDURES, RELIEVE ALL
PRESSURE FROM SYSTEM, ISOLATE THE LIQUID END FROM ALL
SOURCES OF PROCESS LIQUID WITH APPROPRIATE VALVING, AND
PURGE LIQUID END OF ALL PROCESS LIQUID.
1. Disconnect both the suction inlet and discharge
outlet from the piping system.
2. Locate drain pan under diaphragm head to
collect oil. Approximately 1 pint of oil will drain
from the displacement chamber after removal
of the diaphragm.
3. Remove the diaphragm head bolts (1025) which
hold the head to the displacement chamber and
remove diaphragm head (1020). Oil will begin to
leak out. In most cases, the white teflon-faced
diaphragm will remain in the displacement
chamber.
4. Remove the diaphragm. Oil will now drain out
of the front of the displacement chamber.
SECTION 4 - MAINTENANCE