Xylem AC0922 GWT A-C Pump Series Close-Coupled and In-Line Centrifugal Pumps - Manual (Page 2)

READ BEFORE INSTALLING
AND OPERATING PUMP
RECEIPT
INSPECTION – Check pump for shortage and damage immediately upon
arrival. Note damage or shortage on freight bill (bill of lading); immediately
file claim with carrier. Notify the A-C Pump sales office.
Exterior – Pay particular attention to conduit box, external hardware
and accessories. Touch up abrasions or scratches with approved paint.
By hand, test that shaft rotates freely.
Interior – If extensive or serious external damage is noted, impel-
ler is damaged (look in ports), or shaft binds or sticks, disassemble as
required to permit internal inspection. Refer to applicable pump and/or
motor maintenance manual for procedures.
Handling – Handle with care. Dropping or jarring can seriously dam-
age motor bearing or break pump parts. Lift with device with capacity for
pump weight, and use lifting hooks or eye bolts (if provided) or rig double
sling around motor frame and pump casing. Do not use sling through
pump-motor adapter nor around suction and discharge flanges.
Storage – Store pump in clean, dry, well ventilated area, free from
rapid or wide changes in temperature. Suitably cover to keep chips, de-
bris, dirt, dust from pump. Make sure heavy objects will not drop or fall on
pump. For storage of 6 months or longer:
1. Coat exposed, machined surfaces with rust-preventive.
2. Consult applicable motor or pump maintenance manual for pro-
cedures to follow if atmospheric conditions are poor. (51x3963).
3. Rotate shaft several revolutions at least once each 6 months; once
each month if conditions are poor.
4. Relubricate motor bearings every 2 years.
5. At the very least, drain moisture from TEFC motors regularly. Best to
use desiccant and/or heaters to keep moisture from accumulating.
6. After long storage, particularly if conditions were poor, thoroughly
clean, and dry, motor and pump before placing in service.
INSTALLATION
Location — Pump location should provide the following:
1. Install as close to suction supply as possible.
2. Shortest and most direct suction pipe practical. Suction lift must
not exceed limit for pump. NPSH available must equal or exceed
pump requirement.
3. Suction port below pumping level to provide priming.
4. Plenty of room for inspection and maintenance.
5. Easy protection from freezing when idle in cold weather.
6. Correct power supply to motor; all wiring should meet National
Electrical and Local Codes and regulations.
7. If outdoors, protection from elements.
Base – Use a substantial base for horizontal shaft pumps; isolate if
necessary, to keep vibrations from pump. Shim under feet to make shaft
level. Check pump flanges with spirit level. Dowel the feet.
For vertical-shaft pumps that are wall, tank, or bracket mounted use a
heavy rugged support that does not deflect when pump is mounted, nor
when pump is running.
Piping – Suction and discharge gauges are useful to check pump op-
eration and are excellent trouble indicators. Install gauges in the lines if
pump nozzles do not have gauge taps. Observe these precautions when
installing piping:
1. Support close to, but independently of pump.
2. Use at least next larger pipe size for suction and discharge.
3. Keep as straight as possible, with few or no bends and fittings.
4. Remove burrs, sharp edges, ream pipe cuts, and make joints
air-tight.
5. Do not “spring” pipe to make connections. Strain must not be
transmitted to pump.
6. Allow for pipe expansion with hot fluids; expansion joints are not
recommended.
Suction – Size and install suction piping to keep pressure loss at mini-
mum and to provide correct NPSH.
1. Straight length not less than 10 times suction pipe diameter should
be provided at pump connection.
2. Size must never be smaller than suction port; for long runs use 1 or
2 sizes larger.
3. Pipe should slope upward to pump, even for horizontal run.
4. Use eccentric reducer at pump, eccentric side down.
5. Use 45-degree or long sweep 90-degree elbows.
6. Use flapper type foot valve, but only to hold prime when pump is
shut down and suction level is below pump.
7. Use gate valves only, for parallel connection and for isolating pump
when shut down. Stem must be horizontal or slope down. Never
use globe valves in suction line.
Discharge - Some close-coupled pumps permit discharge port loca-
tion at any of four positions, 90 degrees apart. Change by removing cover
bolts, rotate casing, and replace bolts. Be sure there is adequate clear-
ance with selected position - wall or tank, motor conduit box, for bearing
lubrication, casing may extend beyond base or feet.
1. If discharge line is short, size may be same as discharge port; if
long, use 1 or 2 sizes larger.
2. For long horizontal runs keep grade as even as possible, avoid
high spots and loops. Trapped air will throttle flow and may result
in erratic pumping.
3. Install check and gate valves in discharge line, check valve (if used)
between pump and gate valve.
External-Injection Liquid – For packed stuffing boxes if pumped
liquid will damage or deteriorate seal material, suitable clean liquid must
be supplied from an outside source. Install valves in this piping to regulate
flow and pressure to the box.
Stuffing Box — For packed pumps the stuffing box must have
clean, clear liquid to flush and lubricate packing. The best means of
assuring this is regulation of seal liquid pressure. In general, provide
external liquid at 15 to 25 psi above pump suction pressure. If pumped
liquid is used, adjust needle valve to give pressure 5 to 10 psi above
maximum box operating pressure (must be found by trial). It is not pos-
sible to adjust this pressure on internal-liquid seal pumps not fitted with
needle valves.
Adjustment or special procedures are not required for pumps
having mechanical seals.
OPERATION
Pre-Start - Before initial start of the pump, check as follows:
1. Be sure that pump operates in direction indicated by the arrow
on the pump casing (suction cover). Check rotation each time
motor leads have been disconnected.
2. Check all connections to motor and starting device with wir-
ing diagram. Check voltage, phase, and frequency of line circuit
with motor nameplate.
3. Check suction and discharge piping and pressure gauges for
proper operation.
4. Turn rotating element by hand to assure that it rotates freely.
5. Check stuffing box adjustment, lubrication, and piping.
6. Assure that motor bearings are properly lubricated.
7. Assure that pump is full of liquid (primed).
Priming – If pump is installed with a positive head on the suction,
prime by opening suction valve and allowing liquid to enter the casing,
at the same time venting all air out of the top of the casing.
If pump is installed with a suction lift, priming must be done by
other methods, such as foot valves, ejectors, or by manually filling cas-
ing and suction line.
CAUTION – DO NOT RUN PUMP DRY WITH HOPE IT WILL SELF-
PRIME. Serious damage may result if started dry.
Starting – Proceed as follows to start pump:
1. Close drain valves and valve in discharge line.
2. Open fully all valves in the suction line.
3. Turn on seal water to the stuffing box (for external-injection). (If
pumped liquid is dirty or if inleakage of air is to be prevented,
this line should be always left open.)
4. Prime the pump. If pump does not prime properly, or loses
prime during start-up, shut down and correct condition before
repeating procedure.
5. For pumps moving high temperature liquids, open warm-up
valve to circulate liquid for preheating. Close valve after pump is
warmed up.
6. Start the motor (pump).
7. When pump is operating at full speed, open discharge valve
slowly.
8. Adjust seal-liquid valves to produce a pressure of 15-25 psi
more than pump suction pressure.
Running – Periodically inspect pump while running, but especially
after first start, and following repair.