Xylem IM129 R01 BF03S - Manual (Page 6)

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4. Disconnect the suction pipe at the check valve. Push the
valve stem with your finger to be sure it operates freely
and no foreign matter is present to prevent it seating.
5. Disconnect tube from air valve and place tire valve cap
on end of air valve. If pump primes OK it indicates that
the tube connections have been damaged and allow air
to leak into the suction of the pump. When reconnect-
ing copper tubing be sure threads are not crossed and
the connections are made air tight. See Procedure and
Diagram for making these connections.
VACUUM GAUGE METHOD FOR
TESTING SUCTION
Disconnect air volume control tube from air valve in pump
chamber. Remove air valve and insert vacuum gauge in 1 ⁄
8
"
pipe tapped opening in back plate. See figure 1. Run the
pump. If while pump is running, gauge does not register
vacuum it indicates:
A. Leak or leaks in the suction line.
B. End of suction pipe is not submerged.
If gauge registers a vacuum of 25" or more it indicates:
A. Plugged strainer on end of suction line or
strainer is buried in mud.
B. Suction check valve plugged or inoperative.
C. Too high a suction lift for satisfactory operation.
If gauge registers a vacuum in feet that is less than the
vertical distance between the pump and the water in source
of supply, it indicates a leak which must be located and
eliminated. Most frequent causes of leaks in suction line are
ground unions, split pipes and fittings. Check these sources
for leaks first and repair them.
Remove vacuum gauge. Replace air valve. Reconnect
copper tube making sure all suction side connections are
tight, as they must be air tight.
If pump fails to function after vacuum gauge is removed
and air volume control is reconnected it indicates the tube
connections are not air tight.
IF PUMP DELIVERS WATER BUT PRESSURE SWITCH
DOES NOT STOP PUMP WHEN WATER IS NOT
BEING USED
To determine cause of the condition, proceed as follows:
1. Close valve in house piping system if one is installed. If
pump stops it indicates leaks in house piping. Examine
toilet flush valves, faucets, etc., for leaks.
2. Check motor rotation. Make sure that motor runs in
direction indicated by arrow on pump casing cover.
3. Check for excessive suction lift. To do this, see vac-
cum gauge method under section “IF PUMP RUNS BUT
DOES NOT DELIVER WATER”, page 5. If suction lift
is beyond suction limits of pump, provision must be
made to reduce the suction lift by placing pump closer to
source of supply.
4. Pressure switch may need readjustment. See instructions
for setting pressure switch.
5. Check suction line for air leaks. See paragraph under
section “IF PUMP RUNS BUT FOES NOT DELIVER
WATER”, for method of doing this.
6. Air volume control tubing or fitting may be leaking air.
7. The nozzle might be plugged. In order to make a proper
examination of the nozzle and venturi, they must be
removed from the pump. To do this:
A. Disconnect power from pressure switch, close
gate valve in house piping and drain pump.
B. Remove 8 tap bolts holding case cover to case
and lift off rotating element assembly including
motor and case cover.
C. Disconnect the suction and discharge pipes and
copper tube from air valve.
D. Remove the 4 tap bolts holding the back plate
with nozzle and venturi to cushioning chamber
and remove this assembly from the chamber.
E. Venturi can be readily unscrewed and taken out
with a strap wrench or small pipe wrench.
F. To remove the nozzle use a 5 ⁄
8
" socket wrench.
G. Check number stamped on nozzle. This should
be 015.
When replacing nozzle and venturi be sure they are
screwed in tightly as the shoulder of each must fit tight
against the machined surface of the back plate in order to
give the proper spacing of these parts, which is very impor-
tant for the satisfactory operation of the pump.
NOTE: It is recommended that thread on the plastic
venturi be lubricated with water. Be sure thread
starts properly and venturi is screwed in up to
shoulder.
When reassembling the pump be sure the
gaskets are in good condition and properly
placed and that the guide vane seal ring is in position on the
venturi.
IF, AFTER PUMP HAS BEEN IN SERVICE FOR SOME
TIME, IT PUMPS WATER BUT DOES NOT SHUT OFF
WHEN WATER IS NOT BEING USED.
If pressure switch has been adjusted several times over a
long period of time and the condition is not corrected, it
is probable that the radial clearance between impeller hub
and guide vane is excessive. Remove rotating element and
check this clearance. If clearance is excessive (more than
.020") or parts are deeply scored they should be replaced.
Install a new guide vane and impeller which will restore
pump to its original condition.
IF PUMP STARTS AND STOPS FREQUENTLY WHEN
WATER IS NOT BEING USED
1. Examine entire house piping system for leaks such
as dripping faucets and leaky flush tank valves and
eliminate any leaks.
2. Examine suction check valve. An obstruction on seat
would permit water to drain out of pump and cause
pump to start frequently. Make sure that suction check
valve stem moves freely in guide and that valve seats
tightly.
3. This condition of frequent starting and stopping when
water is not being drawn may be due to a lack of air in
the air cushioning chamber which may be caused by
improper operation of the Air Volume Control or
Air Valve.
CAUTION