General Pump VF Owner Manual - Manual (Page 12)

GENERAL PUMP
A member of the Interpump Group
VF SERIES
Page 12
10. START-UP AND OPERATION
9.11 Transmission Definition (continued)
c) Set belt tension according to the Manufacturer’s
recommendations; an excessive value will abnormally
stress the bearing, reduce its duration, and cause
premature wear of the pulley. The tension value
depends on different variables as indicated in
paragraph 9.12.
d) Belt length has a natural tolerance ≥ ± 0.75%; for this
reason the three belts must be purchased in pairs.
e) Follow the belt tension direction as indicated in fig. 11;
for different needs, please contact the Customer
Service Department.
f) Carefully align driver pulley and driven pulley races.
9.12 Definition of Belt Static Tension Values
Static tension depends on:
a) The center distance between the two pulleys (belt
length).
b) The load due to the belt’s static tension
c) The number of belts
d) The angle of wrap of the smallest pulley
e) Average speed
f) Etc.
For belts with an XPB profile, the diagram in fig. 12 allows
to obtain the values of the static tension that must be
applied vs. the center distance between pulleys.
fig. 12
Conclusion: using a dynamometer, by loading the belt with
75 N as indicated in fig. 13, you will obtain a flexion value
“te” of about 10.8 mm
Note: If not differently indicated by the belt manufacturer,
the inspection of the correct tension value, and the related
tension adjustment if needed, is to be carried out after at
least 30 minutes of operation in order to obtain belt
settling. The best efficiency and maximum duration is
obtained with a correct tension value.
10.1 Preliminary Inspections
Before Start-up Be sure that:
The suction line is connected and up to
pressure (see paragraphs 9.4-9.5-9.6) the pump
must never run dry.
1. The suction line must be perfectly airtight.
2. All the On-Off valves between the pump and
the feeding source are completely open. The
delivery line must discharge freely in order to
allow the air in the pump to be expulsed
easily, thus facilitating pump priming.
3. All suction/delivery connections and fittings
must be correctly tightened.
4. Coupling tolerances on the pump/transmission
axis (half-joint misalignment, Cardan
inclination, belt tightening, etc.) must remain
within the limits indicated by the transmission
Manufacturer.
5. The oil level in the pump must be verified
using the correct dipsticks (position 1, fig 14),
and especially using the oil sight glass
(position 2, fig. 14).
Ref 300662 Rev.C
06-12