PIETRO FIORENTINI REVAL 182, Use And Maintenance Instructions

Page: 53 / 404

53
REV
AL 182
Use, maintenance and warning instructions
MEDIUM PRESSURE REGULATOR | DESCRIPTION AND OPERATION | REV. 00
EN
13
4
5
A
8
16
B
C
10
11
1
9
6
15
2
U
pstream pressUre
D
ownstream pressUre
L
oaDing pressUre
Fig. 4.13. REVAL 182 with HB/97 incorporated slam-shut valve
OPERATION:
At no pressure, the valve plug (1) is kept in the shut-off position by the spring (10) and rests on the reinforced gasket (11).
The upstream pressure (Up) reaches the HP2/2 bypass device (4) and the upper head (A) of the R44/SS regulator (5) to
prevent inappropriate resetting of the valve. By adjusting the activation button (13) of the bypass, the pressurised gas is
filtered and feeds the AR100 lamination valve (6), which in turn supplies:
• the chamber of the adjustment spring (B);
• the R44/SS regulator (5), calibrated at a pressure of 4.5 bar to overcome the force of the shut-off spring (15) of the
main valve.
Pressing the reset button (16) acts on the pressure switch coupling (9), so that the 3/2 valve (8) can be opened:
• pressurisation of the chamber (C) of the slam-shut valve by the R44/SS regulator (5);
• the plug (1) to open.
In the event that the downstream pressure (Pd) increases or decreases, the pressure switch coupling (9) moves to:
• discharge the pressure from the chamber (C) into the atmosphere through the 3/2 valve (8);
• allow the spring (10) to bring the plug (1) to the shut-off position.