Crane Weinman B Series, Installation And Operation Manual

5

5. DOWELLING

After the unit has been running about one week the 
coupling halves should be given a 

fi

 nal check for 

misalignment, caused by pipe strains or temperature 
strains, If the alignment is correct, both pump feet and 
driver should be dowelled to the baseplate.

6. PIPING

The pump suction and discharge connections are not 
intended to indicate the required suction and discharge 
pipe sizes. The pipe diameter must be selected according 
to the requirements of the pumping system and 
recommended friction losses for the liquid being pumped.

Usually, it is advisable to increase the size of both the 
suction and discharge pipes at the pump nozzles to have 
minimum acceptable friction loss, suction pipe should 
never be smaller in diameter than the pump suction 
nozzle. When suction pipe is of larger diameter than the 
pump suction nozzle, an eccentric reducer is required 
to eliminate possible air or vapor pockets at the pump 
suction inlet.

Both suction and discharge pipes must be supported 
independently near the pump, so that when piping is 
connected to the pump, no strain will be transmitted to the 
pump. Piping should be arranged with as few bends as 
possible, and, preferably, with long radius elbow whenever 
possible.

SUCTION PIPING

A horizontal suction line must have a gradual rise to the 
pump. Any high point in the suction pipe can become 

fi

 lled 

with air and prevent proper operation of the pump and 
may cause loss of prime. The pipe and 

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 ttings must be 

free of all air leaks.

Any valves or 

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 llings should located at a distance equal 

to 5 to 10 times the diameter of the suction pipe from the 
pump suction nozzle. If an elbow must be installed at the 
pump suction, it should be installed in a vertical position 
to reduce unequal 

fl

 ow into the pump, which may cause 

cavitation in the pump. 

NOTE:

 A gate valve in the suction 

piping should not be used as a throttling device, as this 
may cause the liquid to overheat during operation.

7.   WIRING

For electric motor drives, connect power supply to 
conform with national and local codes. Line voltage and 
wire capacity must match the ratings stamped on the 
motor nameplate.

8.   ROTATION

Before starting the pump, check the required direction 
of rotation of the pump. The proper direction is indicated 
by a direction arrow on the pump casing. Separate the 
coupling halves, then start motor to see that it rotates in 
the direction required by the pump. If it does not, reverse 
any two main leads of the 3-phase wiring to the motor.
The coupling halves can be reconnected and the pump 
primed for starting.

C - OPERATION

1. PRIMING

CAUTION:

 Before starting the pump, the casing and 

suction line must be 

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 lled with liquid, and air-vented 

through the vent pipe plugs. The pump must not be run 
until it is completely 

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 lled with liquid, because of danger 

of injuring some of the parts of the pump which depend 
upon liquid for lubrication. The discharge gate vale should 
be closed during priming. Be sure the stuf

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 ng box packing 

or mechanical seal and power frame are supplied with the 
proper lubrication. See LUBRICATION.

2. STARTING THE PUMP

On initial start up, the gate valve in the discharge piping 
should be closed and slowly opened after pump is up 
to speed and pressure developed. 

DO NOT

 operate 

pump for any appreciable length of time against a 
closed discharge valve, as this may heat trapped liquid 
excessively and damage the pump, packing or seal.

The following important items should be checked as pump 
is started and placed in operation.

a. Pump and driver securely bolted.
b. Coupling properly aligned.
c. Piping complete.
d. Correct pump rotation.
e. Pump shaft turns freely.
f.  Discharge valve closed.
g. Suction valve open (if used).
h. Seal water valve open (if used).
i.  Pump fully primed.
j.  Pump and driver properly lubricated.
k. Liquid drips slowly from packing gland.

Only after these items have been checked should the 
pump be started.

3. PUMP  ADJUSTMENT

Open discharge valve as soon as operating speed has 
been reached. After the pump has been started, the 
packing box gland should be tightened to eliminate 
excessive liquid loss. (Applies only to pumps using 
packed stuf

fi

 ng boxes). Packing should not be pressed 

too tight, as this may result in burning the packing and 
scoring the shaft sleeve. The best adjustment will allow 
the liquid to drip slowly from the packing box gland. This 
will permit proper lubrication of the packing and dissipate 
generated heat.

As soon as the pump and driver have reached the normal 
operating temperature, the unit should be shut down for 

fi

 nal coupling alignment. This should be done by following 

the instructions found in Section B, Part 3. If correction 
is necessary, it may be accomplished by the addition or 
removal of shims from under the motor mounting feet.