20
4.0 MAINTENANCE
4.1
Diaphragm Replacement
Disconnect AC power to the pump and disconnect the suction tubing, discharge tubing, and air
vent tubing. Remove the four head bolts with a 4mm or 5mm hex wrench. Turn the stroke
length knob fully counter-clockwise. Unscrew the diaphragm and remove its retainer (small
disk behind the diaphragm).
CAUTION
:
There may be small brass spacers between the retainer and the armature shaft.
These spacers need to be reused when replacing the diaphragm.
Install the new retainer and diaphragm on the shaft. Turn the diaphragm clockwise until it
bottoms on the shaft. Use caution when handling the diaphragm – the PTFE surface can be
damaged by tools, nails, or any sharp objects. Replace the pump head and tighten the head bolts
to a torque of 19 lb-in (2.16 N-m).
4.2
Valve Replacement
Remove the suction and discharge tubing making sure discharge side has been depressurized.
Remove the suction fitting, two valve cartridges, o-ring and gasket(s). Install the new o-ring,
gasket(s) and valve cartridges. Be sure both valve seats are in the same orientation. Refer to
Figure below. Tighten the suction fitting. Similarly remove and replace the discharge valve
cartridges, o-ring and gasket(s). For a more detailed drawing, refer to the Section 6.0.
4.3
Tubing
Check ends of tubing for splits, cracks, or thin spots. Examine the full length of tubing for
damage due to chafing, abrasion, stress cracks, excessive temperature or exposure to ultraviolet
light (direct sunlight or mercury vapor lamps). If any signs of deterioration exist, replace the
entire length of tubing. It is a good idea to replace discharge tubing on a regular preventive
maintenance schedule every 12 months.
CAUTION:
Before working on the pump, disconnect the power cord, depressurize the
discharge tubing and drain or flush any residual liquid from the pump head and valves.
Always wear protective gear when working around chemicals.
CAUTION:
There are many small
parts in the liquid end. These parts
must be installed correctly for
proper operation of the pump.
FLOW
VALVE CARTRIDGE ORIENTATION
Valve Seat
Valve Guide
Valve Ball
