M&C TechGroup MP47-Z_Ex Operator's manual - Handbuch (Seite 47)

Diaphragm Pumps PJ19423-726 Servicing
Translation of Original Operating- and Installation Instructions, english, KNF PJ19423-726 02/13 19
Procedure
The position letters in the following text refer to fig. 4.
Preparatory steps
1. Mark the position of housing A, the head B and pressure plate
C relative to each other by drawing a line with felt-tip pen to
ensure proper assembly.
2. Mark the position of valve body F, clamp ring E and the pres-
sure plate C relative to each other by a drawing line. After-
wards mark the position of valve body G.
3. Unscrew the four cheese head screws M and remove the
cover N.
4. Unscrew the six allen screws D and the four allen screws H,
and remove the complete pump head from housing A.
Replacing valve bodies and valve plates
1. Loosen valve bodies F and G with a socket wrench and re-
move them.
2. Take sleeve U out of both holes of head B and put one new
sleeve into each hole. For the position of sleeves see detailed
view in Fig.4.
3. Put a new valve plate T into each of the valve bodies F and G.
Observe the correct position of the valve plates (see detailed
view in Fig. 4):
Pressure side of the pump: The six projections face upwards.
Suction side of the pump: The six projections face downwards.
4. Fit a new O-ring S to each of the new valve bodies F and G.
5. Screw the new valve bodies F and G into head B and tighten
them moderately with a socket wrench.
6. Lay the clamp rings E on head B; tighten the three allen
screws D only very moderately (they will be tightened firmly in
a later step).
Change molded diaphragm
1. Unscrew the molded diaphragm K from the inside thread of
connecting rod L by turning it anticlockwise by hand. If there
are spacers on the thread of the molded diaphragm, remove
them and put them on the thread of the new molded dia-
phragm.
2. Screw the new molded diaphragm K into the connecting rod L
and tighten firmly by hand.
If the molded diaphragm is overstretched the Teflon coating
can come off.
Final steps
1. Turn the counterweight P until connecting rod L is in mid-
position. Seat the bead of molded diaphragm K correctly in the
groove in housing A.