High vacuum pumps, exhausters and blowers operating manual
17
5 – ACCESSORIES
5.1
– RV VACUUM RELIEF VALVE SETTING INSTRUCTIONS
The vacuum relief valve is an accessory available for blowers and exhausters in order not to generate an excessive
lowering of absolute pressure on suction side. Fit the valve on suction side of the blower/exhauster and prearrange a
pressure take-off closed to the suction side of the same.
Release screw ‘I’ and discharge the valve spring by screwing off
nut ‘L’.
Start the blower and throttle the suction upstream the valve till you get the worst working conditions (usually pipe line
completely closed ).
Screw in nut
‘L’ till you get the maximum vacuum allowed; this can be noticed from the pressure intake on blower's head.
Tighten nut ‘I’ by keeping steady nut ‘L’.
Remove the choking from suction pipe. See fig. 11.
5.2
– SETTING OF THE OVER PRESSURE VALVE
The overpressure valve is an accessory available for blowers in order to avoid overloading of the pump, if there were
any conditions of excessive backpressure in delivery.
The valve is usually supplied non-adjusted.
The setting adjustment is to be performed on the operating system: start the system with a minimum pre-load of the spring
increasing it by tightening the nut
1
until the desired pressure is reached. Then rotate the threaded ring
5
in order to
stabilize the discharge. Tighten finally the nut
1
and bolt
4
(Fig. 12).
5.3
– AIR FILTER ON SUCTION
It is always recommended but it is needed when the blower works in a dusty environment or when there is risk of foreign
objects. (filtering degree < = 0,005 mm)
5.4
– CHECK VALVE
It prevents counter flow or attraction of foreign objects or liquid into the machine
.
5.5
– SILENCERS
The noise emission level of the compressor depends on the rotation speed and the back pressure.
In case of use as a blower, it is necessary to apply a silencer on the intake side in order to reduce the noise. A further
reduction is achieved with a silencer on the delivery side.
Fig. 11
Fig. 12
