Design And Principle Of Operation - Samson 2488 N Mounting And Operating Instructions

Design and principle of operation

1 Design and principle of
operation
The device combines a Type 2488 N Flow
Regulator and a Type 5857 Electric Actuator.
The electric actuator is attached to the valve
by means of the connecting piece and allows
also the temperature to be controlled by
changing the position of the restriction in re-
sponse to the control signal received from an
electric control device. The medium flows
through the valve in the direction indicated
by the arrow on the valve body. The flow
rate depends on the flow passage defined by
the valve plug (3) and the restriction (11).
The integral positioning spring (5) determines
the upper differential pressure (0.2 bar). The
high pressure upstream of the restriction (11)
1 Valve body
2 Seat
3 Valve plug
4 Plug stem
5 Positioning spring
6 Diaphragm actuator
7 High-pressure control line
8 High-pressure side
9 Operating diaphragm
10 Low-pressure side
11 Restriction
12 Restriction stem
13 Set point screw
14 Connecting piece
15 Spring
16 Electric actuator
17 Coupling nut
18 Actuator stem
Fig. 2 · Schematic diagram
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EB 3136 EN
is transmitted to the high-pressure side of the
diaphragm actuator through the control line
(7). The low pressure downstream of the re-
striction acts on the low-pressure side of the
operating diaphragm (9) via a bore in the
valve plug. The differential pressure
generated by the restriction (special differen-
tial pressure) is converted into a positioning
force by the operating diaphragm. This force
is used to position the valve plug against the
force of the positioning spring (5). The flow
rate can be adjusted by turning the set point
screw (13).
18
17
15
12
11
2
1
10
9
8
16
14
13
3
4
5
6
7