Design And Principle Of Operation - Samson 2489/58 Series Mounting And Operating Instructions

Design and principle of operation

3 Design and principle of oper-
ation
Î See Fig. 3
The flow regulator with connection for
additional electric actuator and control
thermostat consists of the Type 2489 Flow
Regulator, the TROVIS 57xx/Type 58xx
Electric Actuator and the Type 2430 Control
Thermostat. The valve is fitted with a
connecting piece (8) for connection of an
electric actuator and the control thermostat.
As a result, it is possible to transmit the
control signal of an electric control device
(flow rate) and a control thermostat
(temperature). The entire regulator assembly
is used to maintain the flow rate and
temperature constant at their adjusted set
points.
The valve closes as the controlled variables
(flow rate and/or temperature) rise.
NOTICE
!
Types 5824-10, 5827-x1 and 5825-10
Electric Actuators with a 7.5 mm rated travel
are used for valves in sizes DN 15 to 25.
Types 5824-20, 5827-x2 and 5825-20
Electric Actuators with 12 mm rated travel
are required for valves in valve sizes DN 32
to 50.
14
Note
For higher temperatures and the resulting
thicker insulation of the valve, mount an
intermediate insulating piece (order no.
1992-3132) between the connecting piece
and actuator.
The medium flows through the valve in the
direction indicated by the arrow on the valve
body. The flow rate is determined by the ar-
ea released by the valve plug (3) and the
adjustable restriction (8.5 or 8.6).
The installed set point spring (5) determines
the differential pressure across the restriction
of 0.2 bar. The pressure upstream of the re-
striction (8.5 or 8.6) is transmitted over the
control line (11) to the upstream pressure
side of the actuator. The pressure down-
stream of the restriction acts on the low-pres-
sure side of the operating diaphragm (6.1)
through a hole in the valve plug. The differ-
ential pressure generated across the restric-
tion is converted into a positioning force by
the operating diaphragm. This force is used
to move the valve plug depending on the
force of the set point spring (5). The flow rate
is adjusted at the set point screw (8.3) or set
point adjuster (8.2).
EB 3135-2 EN