PIETRO FIORENTINI HBC 975, Руководство пользователя, Страница: 64 / 156

64
HBC 975
EN
Use, maintenance and warning manual
SLAM-SHUT VALVE | COMMISSIONING | REV. 00
8.5.2 - CALIBRATION PROCEDURE FOR PRESSURE SWITCHES MOD. 100 FOR LINE OFF 2.0
8.5.2.1 - CALIBRATION PROCEDURE WITHOUT MAIN REGULATOR
11
13
17
15
10
16
Fig. 8.12. Calibration of pressure switches Mod.100
SPRING CALIBRATION FOR MAXIMUM PRESSURE TRIP
Step Action
1 Disconnect the sensing line between pressure switch and line.
2
Increase the pressure in the pressure switch head, using an external pressure source to verify correct calibra-
tion.
NOTE!
Check the pressure by referring to the additional pressure gauge on the external source used
for calibration.
If the slam-shut valve:
• trips before the expected pressure value: screw in (clockwise) the adjustment ring nut (13)
so as to further compress the spring (11);
• does not trip at the expected pressure value: unscrew (anticlockwise) the adjustment ring
nut (13) so as to relieve the spring (11).
3 Decrease the pressure in the pressure switch head.
4 Trigger the slam-shut device by operating the lever in the 3/2 valve (fig. 4.1, ref. 8).
5
Repeat steps 2-3-4 at least three times.
NOTE!
The calibration value must comply with the operating limits specified on the plate.
6 Disconnect the external pressure source from the pressure switch sensing line.
7 Reconnect the sensing line between pressure switch and line.
Tab. 8.39.