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Idiomas disponibles
PR600
2
Operation
The pressure sustaining/relief valve PR600
is controlled by a normally close diaphragm
actuated two ways, spring loaded, adjustable
pressure sustaining/relief control pilot, set to
maintain a constant maximum inlet pressure
from the main valve.
The set point of the upstream pressure,
which is sensed under the pilot diaphragm,
is adjustable within the indicated spring
range of the pilot.
As upstream pressure increases, the
diaphragm pushes against the spring,
allowing the pilot poppet loaded by an
auxiliary spring to be pulled towards its
opened position, allows the fl ow through
the pilot. This allows the main valve to
modulate towards opening. In this way the
valve controls upstream pressure increase
carrying it back to adjusted values.
As upstream pressure decreases, the control
pilot throttles towards close, modulating the
main valve toward close.
Table of contents
Page 2
Operation
Page 2
Mounting
Page 3
Installation
Page 3
Drawing PR600
Page 4
Maintenance
Page 4
Pressure Sustaining/
Relief Pilot PV20-C
Mounting
Mounting must be carried out, as far as
possible, according to the drawing below.
The choice of the proper "by pass" alterna-
tive must be taken considering the following
points:
a. Can the main transport/feeding line be
put out of service during some hours
(corresponding to the requested time for
maintaining the MAIN VALVE), without
generating problem for the exploitation
of the system? In particular, it must be
considered that an empty system may
require several days to be vented
properly.
b. Has the downstream zone of the system
to be protected against any risk of
pressure surge (quick closing of heavy
demands, closing time of pressure
sustaining/relief valve)?
In order to get the best accuracy from the
pressure sustaining/relief valve operation,
the pre-set values for the maximum up-
stream pressure should be included in the
indicated range of the pilot valves. If it is
very near to the extreme limits of replace the
spring by the correct one.
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