5
D4 0617GB
December 2000
Sectional view
521
520A
521A
509
520
507
451
501
451A
376
463
463A
1002
(102)
(202)
395A
395
1030
(139) 506
602
609A
453
453A
5510
557
497A 556 (497) 614 615 611 608 605 455 609
556 453
453A
551
489 382 391
391
453
453A
551
423
427A
427
428
428A
491
489
xxBE
size 025
xxTE
xxJE
602
601
608C
608D
608B
453
453A
5510
557
615
612
497A 556 (497) 614 608 605 608A
124
124A 124B (139A)
Fig. 2
Inspection of rotors
If the pump is not able to maintain the pressure
inspect the rotor parts by following the instructions
in fig. 10-11.
Internal clearances in the pump, which are vital for
its proper function, may have been affected by wear.
Acceptable wear can be determined only by experi-
ence of the actual application. As a rule of thumb the
following max clearance values may apply:
• Between rotor and bores or bushings: 0.2 mm
• Between rotor flanks: 0.2 mm
For light duties (low pressure, medium viscosity)
even bigger clearances may be acceptable whilst for
low visc. /high pressure duties the limit will be
lower. Also check if there are major scratches on
these parts. If you find any of these problems,
replace the whole pump element, otherwise reas-
semble the pump by following the instructions in
fig. 12 and forward.
xxBP size 060-070
xxBP size 025-032
xxBP size 038, 045, 052
