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OPERATION
FLUSHING THE PUMP
NOTICE:
If flushing fluid is to be left in the pump for an extended
time, it must be a lubricating, non-corrosive fluid. If a
corrosive or non-lubricating fluid is used, it must be
flushed from the pump immediately. Water is not
suitable to remain in pump after flushing.
1. To flush the pump, run the pump with the discharge
valve open and the intake valve closed. Bleed air into
the pump through the intake gauge plug hole or through
a larger auxiliary fitting in the intake piping. Pump air for
30 second intervals to clean out most of the pumpage.
2. Run a system compatible flushing fluid through the pump
for one minute to clear out the remainder of the original
pumpage.
3. To remove the flushing fluid, follow step 1 above.
NOTICE:
After flushing the pump some residual fluid will remain
in the pump and piping.
NOTICE:
Properly dispose of all waste fluids in accordance with
the appropriate codes and regulations.
PUMP RELIEF VALVE
NOTICE:
The pump’s internal relief valve is designed to protect
only the pump from excessive pressure and must not be
used as a system pressure control valve.
The Blackmer pump internal relief valve is designed to
protect the pump for a LIMITED time operation, against a
partially closed discharge valve by allowing internal fluid
recirculation.
An external bypass system is required when operating the
pump for periods greater that one minute against a closed or
partially closed discharge valve.
The pump relief valve must be set higher than the system
pressure control valve, but must not exceed the maximum
differential pressure of the pump (see table 1).
RELIEF VALVE SETTING AND
ADJUSTMENT
The relief valve pressure setting is marked on a metal tag
attached to the valve cover. The relief valve should be set at
least 10-20 psi (0.7-1.4 Bar) higher than the operating
pressure or system pressure control valve, but no higher than
the maximum working pressure of the pump (see Table 1)
Incorrect settings of the pressure relief
valve can cause pump component
failure, personal injury, and property
damage.
Hazardous pressure
can cause personal
injury or property
damage
Relief valve cap is exposed to pumpage
and will contain some fluid
Hazardous or toxic
fluids can cause
serious injury.
DO NOT remove the R /V Cap OR adjust the relief valve
pressure setting while the pump is in operation.
1. To
INCREASE
the pressure setting , remove the relief
valve cap (1) and gasket (88). Loosen the locknut (3), if
equipped. Turn the adjusting screw (2) inward, or
CLOCKWISE. Inspect R/V cap O-ring/gasket (88) and
replace as required. Reattach R/V cap O-ring/gasket and
R/V cap.
2. To
DECREASE
the pressure setting, remove the relief
valve cap (1) and gasket (88). Loosen the locknut (3), if
equipped. Turn the adjusting screw (2) outward, or
COUNTERCLOCKWISE. Inspect R/V cap O-ring/gasket
(88) and replace as required. Reattach R/V cap O-
ring/gasket and R/V cap.
Refer to the individual Blackmer pump parts lists for various
spring pressure ranges. Unless specified otherwise, pumps
are supplied from the factory with the relief valve adjusted to
the mid-point of the spring range.
