34 Disassembly and assembly CR/EN (1004) 4.0
7.5.3 Disassembling the wear rings
After removing the Back-Pull-Out unit (see paragraph 7.4.2 "Disassembling the Back-
Pull-Out unit") the wear rings can be removed. In most cases the ring has been fixed so
tightly that it cannot be removed undamaged.
1 Disassembling the impeller, see paragraph 7.5.1 "Disassembling the impeller"
2 Unlock the set screw (0155) that lock up the impeller wear ring (0150) on the
impeller.
3 Unlock the set screw (0135) that lock up the casing wear ring (0130) on the impeller.
4 Measure the thickness (d) and the width (b) of the ring, see figure 10 A.
5 Make a centre hole in the middle of the edge of the ring at two opposite points, see
figure 10 B.
6 Use a drill with a diameter just a little bit smaller than the thickness (d) of the ring and
drill two holes in the ring, see figure 10 C. Don't drill deeper than the width (b) of the
ring. Take care not to damage the fitting edges of the pump casing and impeller.
7 Use a chisel to cut the remaining part of the ring thickness. Now you can remove the
ring in two parts from the pump casing, see figure 10 D.
8 Clean the pump casing and impeller and carefully remove all bore dust and metal
splinters.
Figure 10: Removal of wear ring.
b
d
ABCD
b
d