9
3) A vacuum pump (preferably a wet vacuum pump) may be
used for evacuating air from the pump and piping. The vacu-
um pump should be connected, as is the exhauster covered in
No. 1 on page 8, and the procedure is the same.
When the source of the liquid to be pumped is above atmospheric
pressure or above the pumps discharge flange, the pump may be
filled by venting through a bleed-off line to the atmosphere. When
the source of the liquid is above the pump’s discharge flange, the
venting could be back to the suction source, instead of to the atmos-
phere. When all of the air has been expelled through the bleed-off,
seal it. Remove the pipe cap from the top of the pipe rising from the
pipe tee which also contains the seal vent plug (refer to the “Small
Piping Connections” drawing on page 7). Discard the pipe cap.
Allow the air to flow from this port until the pumpage starts to flow.
This could take considerable time as the radial bearing clearance,
through which the liquid must flow, is quite small. Several minutes
is not unusual, although sometimes it may vent in less than a minute.
If the pump is a “RWA2096”, use a funnel and fill the seal cavity
through this connection with clean pumpage. Install the vapor elim-
inator assembly into the top of the pipe through which you were
venting. Install the vapor exhaust tubing into the top of the vapor
eliminator. Refer to the “Small Piping Connections” drawing on
page 7.
At any time in the future, when the system is drained and the
pump needs filling, follow the above procedure except remove the
seal vent plug to vent the seal cavity and leave the vapor
eliminator intact.
It is most important to check the direction of rotation of the pump
before allowing the pump to come up to speed.
The pump was
shipped with the coupling spacer not installed to allow alignment
and motor rotation direction check. If, however, someone installed
this spacer assembly, remove it at this time
.
To check rotation direc-
tion, push the starting button and instantly push the stop button. This
will allow the motor to turn over a few revolutions and the direction
of rotation to be observed. A direction of rotation arrow is shown
on the front of the pump casing. If rotation is incorrect, change the
wiring connections and recheck rotation.
Operating the pump in
reverse rotation may cause extensive damage.
WARNING:
Lock-out the power to the driver (motor, turbine, engine, etc.) install
the shaft coupling spacer. Be sure that you install all the retaining
devices and bolts and that they are tight. Read and comply with the
coupling manufacturer’s instructions. Personal injury, death, and/or
equipment damage could occur if the coupling spacer is not prop-
erly installed. Remove all debris and tools from the area near the
shafts and the shaft coupling. Do this to assure that nothing is
caught and thrown by the rotating parts when the pump is started.
Bolt the coupling guard securely to the baseplate, checking to
assure that it is not contacting any parts that will rotate when the
pump is started.
OPERATING
WARNING:
Before starting the unit, see that all personnel are a safe distance
away from all possible hazards, that all sub-systems are connected
and operating, that all debris has been removed, that the shaft
coupling guard is securely in place, and that the pump is full
of liquid.
Do not operate this pump at shut-off (no flow) as an explosion may
result. This can occur with any liquid, even “cold water”. Personal
injury, death, equipment damage, and/or loss of product
(pumpage) is likely to occur. If your system is operated where it is
possible for all outlets of the discharge from the pump to be closed
while the pump is still operating, a modification of the system needs
to be made to assure a continual flow of pumpage through the
pump. NOTE: Some people have a belief that a bypass line from the
discharge side of the pump to the suction side of the pump will
relieve this problem, this is “NOT TRUE”; DO NOT ATTEMPT THIS.
WARNING:
Do not operate a pump at a low flow condition, unless provision has
been made to prevent dangerous heat build up within the pump
casing. The liquid in the pump will heat up and this may result in
high pressure in the pump in a short time. Such pressure may result
in a rupture of the pressure-containing parts and cause severe haz-
ard to personnel and/or damage to the system.
A centrifugal pump should never be run without liquid In the cas-
ing. Extensive damage may result, particularly to the bearing or the
mechanical seal. Vent or fill the pump seal chamber through the seal
vent connection to provide lubrication to the mechanical seal faces.
If the pump is a “RWA4166” or a “RWA4206”, remove the bear-
ing grease relief plug from the bottom of the bearing end cover
(28). Replace the coupling guard and securely fasten it in place.
Make sure that the coupling guard is installed with the expanded
metal section nearest the motor, as shown on the Sectional
Assembly drawings on page 11.
A centrifugal pump should be started with the suction valve
fully open and the discharge valve opened a slight amount. Start
the pump.
As soon as the pump is up to speed, the discharge valve must be
opened slowly. A centrifugal pump cannot be operated with the
discharge valve closed without heating up dangerously. During the
first several minutes of operating watch the pump carefully for over-
heating, vibration, and other abnormal conditions. If trouble
develops, stop the pump at once and correct the problem.
If the pump is a “RWA4166” or a “RWA4206”, stop the pump after
about thirty minutes of operation, replace the grease relief plug into
the bottom of the bearing end cover (28) and tighten to 7 ft. lb.
Replace the coupling guard and securely fasten it in place.
Make sure that the coupling guard is installed with the expanded
metal section nearest the motor, as shown on the Sectional
Assembly drawings on page 11.
Restart the pump.
