38
DIV
AL 600
EN
Use, maintenance and warning instructions
MEDIUM PRESSURE REGULATOR
|
DESCRIPTION AND OPERATION
|
REV. A
OPERATION IN THE EVENT OF FAILURE OF THE MAIN REGULATOR
U
pstream
pressUre
D
ownstream
pressUre
Fig. 4.5. Operation of regulator-monitor with main regulator in faulty conditions
In the event of failure of the main regulator (2), the regulator with monitor function (1) will intervene maintaining the down-
stream pressure value (Pd) within the established limit for its calibration.
If, during operation, the following should occur:
Operating conditions
Operating consequences
Concluding outcome
Decrease in downstream pres
-
sure (Pd) for:
• increase in the requested
flow rate;
•
drop in pressure upstream
(Pu).
Unbalance that causes the plug (3) to
open.
Increase in flow until the preset value
of the downstream pressure (Pd) is
restored.
Increased downstream pressure
(Pd) due to:
•
drop in the requested flow
rate;
• increase in pressure up-
stream (Pu).
Unbalance that causes the plug (3) to
close.
Decrease in flow rate until the preset
value of downstream pressure (Pd) is
restored.
Tab. 4.20
Summary of Contents for Dival 600
Page 156: ...TM0023ENG...
