Rev. 00 of 01.01.2009
24 / 29
11.3.1 FEATURES OF THE VANES:
STANDARD vanes are suitable for short, infrequent, light duty uses. The HEAVY DUTY
(USA STANDARD)
vanes are made of a special material suitable for vacuum pumps
frequently used in industry. These vanes are highly resistant to wear and
thermal/mechanic stresses. They are recommended for frequent uses and for the
suction of thick sewage due to the longer time required to fill the tank. They are
recommended as well for systems used frequently during the same day.
Besides normal wear, vane replacement can be necessary due to a wrong use of the
vacuum pump. The most frequent causes of defects are excessive heat, lack of
lubrication, entry of sewage and/or fine dusts, high pressure or vacuum, creation of rust
inside the body due to lack of use for extended periods.
Excessive heat causes vane thickness to swell which prevents their free exit from the
rotor slots; this issue is more frequent in standard vanes than in heavy duty vanes. If
lubrication is insufficient, the vanes, as well as the inside of the pump, remain dry, they
become brittle and breakage is likely. The same kind of breakage may be caused by the
entry of sewage and/or fine dusts or by excessive operating pressure. Excessive
vacuum causes the beating of the vanes against the cylinder which causes damage to
the external face of the vanes. This also causes a “wave” in the housing cylinder.
11.3.2 INSPECTION OF THE VANES:
To verify the wear of the vanes in the vacuum pump,
proceed as follows:
remove the threaded inspection cap (1), located on
both the drive and driven sides.
rotate the rotor to align a vane with the inspection hole.
measure the distance (2) between the external surface
of the rotor and the external face of the vane.
if such distance is longer than 10-15% of the original
height of the vane, replace the entire series of vanes.
IMPORTANT
: Before inserting the new blades,
carefully check that the vane length matches that of
the rotor slot. If not, contact an authorized dealer.
