Pressure Variator - Riello RLS 280/E Installation, Use And Maintenance Instructions

4.13.2 Pressure variator

The pressure variator (Fig. 22), allows the pressure on the return
line of the nozzle to be varied according to the required output.
The pressure on the return line is adjusted by varying a section by
means of the rotation of the servomotor 23)(Fig. 3 on page 11),
which also controls the gas butterfly valve at the same time.
 Regulator at 0° (maximum opening) = minimum pressure on
the nozzle return line.
 Regulator at 90° (minimum opening) = maximum pressure on
the nozzle return line.
The servomotor is controlled by the electronic cam 1) (Fig. 6 on
page 14); thanks to this device, it is possible to set different curves
for oil and gas on the same servomotor (also for the air damper ser-
vomotor 4)(Fig. 3 on page 11).
 In the oil regulation the regulation is carried out on the basis
of the nozzle that has been mounted and the modulation
required.
Installation
1
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Key (Fig. 22)
1 Nozzle delivery pressure gauge
2 Nozzle return pressure gauge
3 Position indicator (0 ÷ 90) of the pressure variator
4 Maximum oil pressure switch on return circuit
GB
29
4
2
3
Fig. 22
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