26 Installation, Operations & Maintenance Manual
Relief Valve Setting
The Pump must be at operational pressure and
95% capacity setting.
1. Remove yellow plastic plug located at top of
pump next to the oil ll hole.
2. Using a 3/16” hex. key (mRoy A), or a 5/16”
hex. key (mRoy B) as required for the different
models, turn the adjusting screw clockwise to
increase cracking pressure until pump ceases
to bypass through the relief valve at the desired
working pressure. When relieving has stopped,
adjust the screw clockwise up to one full turn
beyond this point to set a reasonable buffer zone
between operating pressure and relief pressure.
To determine if relieving is taking place, insert
your index gure into the oil reservoir opening
and place it against the bypass opening
(Figure 17) where the oil pulse from the relief
valve can be determined.
3. Reinstall the plastic yellow plug
NOTE:
No moving parts are present in the oil reservoir
in this location.
WHEN OPERATING WITH
RELIEF VALVES, ESPECIALLY
ON PUMPS WITH LARGE PLUNGER SIZE, OIL MAY BE EJECTED
AT HIGH VELOCITY FROM THE BYPASS PORT. NORMAL
PRECAUTION SHOULD BE OBSERVED TO PREVENT THIS
FROM SPLASHING THE SURROUNDING AREA.
NOTE:
This relief is intended primarily for pump
protection in the event that the discharge or
suction system is blocked while the pump is in
operation. It is a good practice to install a high-
grade chemical type relief valve in the pump
discharge line as close to the pump as possible,
and always between the pump and any shut-off
valve. Pipe the outlet of the system relief valve
back to the suction tank, with the open end of
the pipe visible at all times. In this way, relief
valve leakage may be easily detected.
SECTION 3 - OPERATION
FOR SAFETY REASONS, A
CHECK VALVE IS
RECOMMENDED FOR USE IN THE DISCHARGE LINE NEAR
THE POINT WHERE THE LINE ENTERS A HIGH PRESSURE
PROCESS VESSEL.
3.3 OPERATION
The mRoy pump is designed for reliable, unassisted
operation. During normal operation, a periodic
check of the pump is recommended every 24 or
48 hours to visually conrm satisfactory operation:
1. Make sure the oil level in the air bleed ller
reservoir is above the oil level mark.
2. Inspect the pump liquid end for indication of
leakage or seepage.
If anything seems to be abnormal, refer to Section
4, Maintenance.
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