4
Filtration Pumps
Filtration Pumps
5
switching it off, to purge out droplets of liquid that may have formed on
the inside of the pump. This prevents crystallization and/or absorption of
liquids by the pump materials, and prolongs pump life.
Spare Parts Kits
Each kit contains the following parts to renew one head:
Qty
Description
1 ................................................................................. Structured Diaphragm
2 .................................................................................................. Valve Plates
2 ..................................................................................................... Seal Rings
For Model
Use Kit ID#:
N86KNP ................................................................................................ 072838
N86KTP, N86KT.45P, N86KT.46P, PU837, PU838 ............................ 072839
N811KNP ............................................................................................. 074626
N811KTP, N811KT.46P, PU840 .......................................................... 074931
N811KVP, N811KV.45P, PU839, MPU953 ......................................... 074178
N816.3KTP*, N816.3KT.45P*, N816.1.2KTP*, N816.1.2KT.45P* .... 077769
N838.3KTP*, N838.3KT.45P*, N838.1.2KTP*, N838.1.2KT.45P* .... 202884
Note:
Each kit contains parts to renew one head. *For twin-head pumps, two kits are
required. Additional replacement parts are availabe through KNF Customer Service:
Replacement Parts
(to order, contact KNF Customer Service)
1
/
4
”Hose Barb Fittings
1
/
8
”NPT
Shim Rings
Pressure Gauge/Regulator Package
Diaphragm Support Cup
Vacuum Gauge/Regulator Package
Spring & Spacer Washers
Troubleshooting
Maximum vacuum is not reached—
1.
Check that all system connections are gas-tight.
2.
Be sure that all screws on the head assembly are snug.
To avoid damag-
ing pump, do not overtighten screws.
3.
Disassemble the valve assembly as described in “Maintenance Proce-
dures”. Look for any foreign matter; commonly bits of Teflon
®
tape or
particulates carried into the valve system or crystallized residue from
previously pumped vapors. All of the above must be cleaned out and the
pump reassembled with clean or new parts.
Pump does not run - pump on/off switch is dark—
1.
Check that power is being supplied to the pump from the power source
and the pump switch is in the on position.
2.
An overcurrent or other problem may have blown the fuses. To check
fuses:
(Fuse holder located next to power socket)
WARNING
Shut off all power to pump before checking fuses. Unplug
pump’s power cord from electrical source.
3.
Pull out the fuse holder while depressing the small tab, and determine if
the fuses are good. The proper replacement fuses should always be
used. Consult the nameplate, or call KNF Customer Service for the proper
rating and type of fuse.
Pump does not run - pump on/off switch is lit—
WARNING
Motor is thermally protected and will automatically restart unex-
pectedly when overload device resets.
1.
It is possible that the thermal protective device has activated. Turn off the
pump and let it cool for 15 minutes before trying again.
2.
If the pump starts, determine the cause of the overload before using the
pump. Possible causes are:
- Electrical power source does not match motor requirements,
- Insufficient ventilation of the motor caused by blockage or dirt,
- Defective pump assembly or motor.
- Application is exceeding the pressure rating of the pump.
Maintenance Procedures
(Refer to exploded view)
Materials needed:
Replacement kit(s)
Tool required:
Small Phillips-head screwdriver, (2-head pump - small adjust-
able wrench,) marking pencil, mild solvent to clean residue from heads.
Cleaning or replacing valve plates, seal rings and diaphragms:
WARNING
Shut off all power before proceeding. Unplug pump’s power
cord from electrical source.
If you run into a problem or have a question regarding the following proce-
dure, please call KNF Application Engineering for assistance.
1.
Be sure pump is dry and free of hazardous materials by operating it for 5
minutes in free air.
2.
Mark the relative position of the head parts with a pencil line to ensure
correct assembly later. It is not necessary to remove the optional pres-
sure gauge, regulator assembly or hose barbs.
3.
Remove the 4 perimeter head screws
B
on the pump head.
4.
Lift the head assembly and rubber skirt straight up and place on a clean,
flat work surface.
To clean or replace the valve system within the head assembly:
(Note:
Certain models have auxiliary screws securing the headparts)
5.
If supplied, unscrew the center screw(s)
P
located in the center of the
pump headplate
A
.
6.
Carefully separate the headplate
A
from the intermediate plate
C
. Two
seal rings and two valve plates are now exposed.
7.
Remove old seal rings
E
and valve plate
D
. Carefully clean any residue
from the valve seats with a mild solvent before proceeding. Do not
