Xylem P81630E Series VSC and VSCS Base Mounted Centrifugal Pumps - Manual (Page 5)

5
VSCS-S
VSCS-PF
VSCS-D
FOR FINE ALIGNMENT, ORANGE HYTREL INSERTS,
3500 RPM OPERATION, OR ALL OTHER COUPLER TYPES
Use a dial indicator when greater alignment accuracy is re-
quired. Use the following alignment tolerances unless specified
otherwise by the coupler manufacturer. On sleeve type couplers
make sure there is about 1 /
8
" end clearance between the sleeve
and the two coupler halves.
1. To check angular misalignment, mount the dial indicator
base to one coupler half, or shaft, and position the dial indi-
cator button on the front or rear face of the opposite coupler
half. Set the dial to zero. Rotate both coupler halves together,
making sure the indicator button always indicates off the
same spot. Misalignment values within 0.004" TIR per inch of
coupler radius are permissible.
2. To check parallel misalignment, mount the dial indicator base
to one coupler half, of shaft, and position the dial indicator
button on the outside diameter of the opposite coupler half.
Set the dial to zero. Rotate both coupler halves together,
making sure the indicator button always indicates off the
same spot. Misalignment within 0.004" TIR is permissible.
PIPING
Always install a section of straight pipe between the suction
side of the pump and first elbow. This reduces turbulence of
the suction by straightening out the flow of liquid before it
enters the pump. The length should be equal to five times the
diameter of the suction pipe size.
Line up the piping so that the bolt-holes in the pump flanges
match the bolt-holes in the pipe flanges. DO NOT ATTEMPT
TO SPRING THE SUCTION OR DISCHARGE LINES INTO
POSITION. Coupling and bearing wear will result if suction or
discharge lines are forced into position. The code for Pressure
Piping (ANSI B.31.1) lists many types of supports available for
various applications.
When considerable temperature changes are anticipated,
equipment for absorbing expansion should be installed in the
system in such a way as to avoid strain on the pump.
When using an isolation base, flexible piping should also be
used on both suction and discharge sides of pump.
On an open-system with a suction-lift, use a foot-valve of equal
of greater area than the pump suction piping. Prevent clogging
by using a strainer at the suction inlet next to the foot-valve.
The strainer should have an area three times that of the suction
pipe with hole diameter of no less than 1 /
4
".
The pipeline should have isolation valves around the pump and
have a drain valve in the suction pipe.
A Bell & Gossett Triple Duty Valve installed in the discharge line
will serve as a check valve to protect the pump from water
hammer, as a gate valve for servicing and for throttling.
PUMP INSULATION
When insulating a Series VSC/VSCS pump, ensure that the
grease fittings remain accessible and visible. Do not seal off the
drain holes in the bearing caps or bearing housings.
PRIMING AND STARTING
Before starting the pump, the pump body must be full of liquid.
Manual priming may be required if the system does not auto-
matically fill the pump body with liquid. Vent plugs are provided
on the pump body to vent the air. While venting the air from the
pump body the pump shaft should be rotated a few times by
hand.
The pump should be started with the discharge valve closed
and the suction valve fully open. After the pump is up to oper-
ating speed the discharge valve should be opened slowly.
IMPORTANT: The pump should never be operated with the
suction valve closed or throttled. This could result in cavitation.
LUBRICATION
Lubricate pump bearings at least twice a year or flush bearings
whenever necessary with NLGI Grade No. 2 mineral base or
lithium base petroleum grease while the pump is running. On
chilled water applications it is important to keep the bearing
cavity full of grease to protect from condensation. Lubricate
motor bearings in accordance with the manufacturer’s instruc-
tions.
GENERAL INSTRUCTIONS
1. Keep this pump and motor properly lubricated.
2. Protect the motor against overload and low-voltage. Use a
motor-starter with proper size heater elements.
3. When there is danger of freezing, remove the plugs at the top
and bottom of the volute shell.
CAUTION: Seal Damage Hazard
Do not run pump dry, seal damage may occur.
Failure to follow these instructions could result in serious
property damage and/or moderate personal injury.