IWAKI PUMPS APN-450, Instruction Manual

Page: 31 / 36

- 29 -
Maintenance
Valve replacement
1. Remove the pump head.
2. Remove all the cover mounting screws to take
out the valve restraint and valve.
Clean valve insertion areas and sealing surfaces
on the pump head.
3. Take out the valve beneath the pump head as
well.
4. Place a new valve and fasten a screw. Note the
valve can not be mounted upside down.
5. Place a new gasket onto the pump head and
secure the cover with the mounting screws by
2.8N•m. Do not forget to attach the gasket or
catch it in the cover.
6. Press down the diaphragm until it bottoms out
and then mount the pump head with 4 hexagon
socket head bolts.
Tighten hexagon socket head bolts in diagonal
order until they bottom out.
7. Follow the same step for the other pump head
of the twin heads type. Replace an optional filter
with new one if it is installed.
Hexagon socket
head bolt
Pump
head
Screw
Filter (option)
Valve
Valve restraint
Screw
Case
Valve
Valve
restraint
Screw
Cover
Gasket
Screw hole
Sealing surface