Armstrong 4280 Series User manual

Series 4280
Motor mounted
horizontal end
suction pump
Service work
instructions
File No: 42.81
Date: december 15, 2002
Supersedes: 42.81
Date: june 15, 2000

service work
instructions
Series 4280 Motor
Mounted Pump
2
Servicing Armstrong Series 4280 pumps
Refer, also, to Armstrong Installation & Operating Instructions
for series 4280 motor mounted pumps: File No: 42.80
All component numbers shown in this document refer to the
sectional view on front cover
The Series 4280 pump is a motor mounted or close-coupled
type pump, mounted on a ball bearing motor. The pump should
be secured to the foundation by means of capscrews inserted,
through the motor feet, into flush type anchors embedded in
the foundation. This is necessary in order to enable the motor
assembly, with pump adapter and impeller to be pulled back-
wards out of the pump casing. when servicing the unit.
breakdown procedures:
1. electrical wiring
caution
Exercise extreme care when handling power wiring.
Ensure that the fuses are removed or breaker discon-
nected in the power line to the motor. Disconnected
power should be within sight of the pump being ser-
viced and tagged with the reason for disconnection.
If the pump and/or motor assembly is to be serviced on a
bench, the motor wiring must be disconnected. This may not
be necessary if the pump is to be serviced in place on the
foundation.
2. isolation valves
If the system is not drained: Ensure that the suction and dis-
charge piping isolation valves are closed. Remove drain plug
[105] from the bottom of the casing and drain the pump.
3. mounting capscrews
The motor mounting capscrews must be removed from the
foundation to permit removal of the rotating assembly out of
the pump casing [100].
4. prepare assembly for removal
Remove the casing capscrews and washers [104 & 103].
Pry bars may then be inserted between the casing [100] and
adapter [40]. Care should be taken not to apply pressure to the
outside diameter of the adapter, to prevent possible breakage.
Outside pressure should be on the casing only.
5. remove rotating assembly
The rotating assembly (motor, adapter and impeller [10, 40 &
80]) may now be pulled back out of the casing.
Prior to removing the rotating assembly ensure that the casing
is supported properly. If flexible connectors are installed in the
piping, support the casing in such a manner as to prevent the
casing weight from hanging on the flexible connectors.
6. rotating assembly notes
The impeller [80] is fastened directly to the motor shaft and
must be removed in order to replace the mechanical seal
[60/62]. This may be accomplished while the pump is still on
the foundation or more conveniently, on a work bench.
7. impeller capscrew
The impeller [80] should be prevented from rotating while
the capscrew [86] is loosened. A heavy screwdriver may be
inserted between the impeller blades to enable the impeller
capscrew to be backed o with a socket wrench. Remove the
impeller capscrew and washer [86 & 83]
8. pump impeller
Using wheel pullers, with the jaws behind the rear shroud of the
impeller [80] (Behind a vane at each side) pull the impeller free
of the pump shaft. Impellers that are dicult to remove may
be loosened by heating the impeller hub with a torch during
the pulling process. Remove the impeller from the motor shaft.
1 3 7
7
8
8
8
4
4
4
6
6 101
100
105
103
104

service work
instructions
Series 4280 Motor
Mounted Pump
3
Note the impeller key and shaft sleeve spacer [71]. Remove
both for storage.
9. remove mechanical seal from motor shaft
The mechanical seal spring usually comes free with the impel-
ler. The mechanical seal rotating element [62] must be pried
loose with pry bars or screwdrivers. Once loosened, the seal
may be pulled free of the shaft.
Do not damage the carbon face when removing the rotating
assembly. It may be needed for analysis if seal failure investiga-
tion is required.
10. remove seal seat from adapter
The mechanical seal seat [60], usually oring mounted Ni-
Resist material, is pried loose from the recess in the adapter.
If the seat cannot be removed in this manner, remove the motor
capscrews [44] and separate the adapter [40] from the motor
[70]. A screwdriver may then be used to push the seat out of
the adapter from the rear.
11. remove old casing gasket
The former casing gasket [101] should be scraped from the
casing and adapter, leaving clean surfaces for the new gas-
ket. A standard putty knife and wire brush are useful for this
purpose)
assembly procedures:
12. replace mechanical seal
Clean the shaft sleeve [70] surface, ensuring all the former
seal elastomer pieces have been removed. Inspect for damage.
Replace if necessary. (See separate instructions for removal of
the shaft sleeve [File No. 6042.25]). Inspect the water slinger
[39] and replace if damaged. Install a new seal seat [60] in
the adapter cavity, being sure the lapped (polished) side of the
insert is facing up. Ensure that the cavity has been thoroughly
cleaned. Lubricate the seat oring with a small amount silicon
or glycerine lubricant and press down, straight and even, into
the cavity. Do not press the seat in with bare fingers, use a
clean cloth or the cardboard disc typically supplied with the
seal. Contamination of the polished and lapped seat face could
cause leakage. If the adapter was removed from the motor,
replace now, taking care that the seal seat is carefully guided
over the motor shaft.
Lubricate the inside of the seal rotating assembly [62] with a
small amount of silicon or glycerine lubricant and slide onto
the shaft sleeve [70] with a twisting motion, carbon face first,
until the carbon face is pressed firmly against the seal seat
[60]. Pressing on the seal rotating assembly metal parts, with
a screw driver, all the way around the seal, will ensure that the
faces are mated properly.
Remove the spring retainer from the seal spring and place the
seal spring over the seal rotating assembly.
13. replace pump impeller
Install the shaft sleeve spacer [71] and impeller key on the
shaft and place the seal spring retainer onto the impeller hub
register. Slide the impeller in place on the motor shaft. Take
care and ensure that the seal spring is kept in place on the
seal rotating assembly and fits well into the retainer on the
impeller hub.
14. tighten impeller capscrew
It is good practice to replace self locking screwa, once removed.
Install the impeller capscrew and washer [86 & 83]. Hold the
impeller the same way as when the capscrew was successfully
loosened (Bar or screw driver placed carefully between the im-
peller blades) and tighten the capscrew with a socket wrench.
15. install new casing gasket
Insert new casing gasket [101] onto the register on the adapter.
16. slide rotating assembly into place
The rotating assembly (Motor, adapter and impeller
combination [10, 40 & 80]) may now be pushed into place in
the casing.
Once in place, any casing supports should be removed.
17. casing capscrews
The casing capscrews [104] are now installed and evenly tight-
ened with a wrench. Tighten the capscrews a little at a time,
diagonally across the casing, to assure even gasket pressure.
18. motor mounting capscrews
The capscrews that hold the pump to the foundation are now
installed and tightened.
19. isolation valves
Replace the casing drain plug and open the suction and dis-
charge isolation valves.

service work
instructions
Series 4280 Motor
Mounted Pump
4
20. motor wiring
The motor conduit and its wiring are now replaced. Be sure to
check rotation of the motor after rewiring if the motor is three
phase and correct if necessary, by switching any two lead
wires.
Ensure that the pump is filled with water before operating to
check rotation.
21. conduit box cover
The conduit box cover is replaced after checking the motor
rotation. The pump may now be placed in operation.
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