12
EB 2520 EN
Design and principle of operation
3
Design and principle of oper-
ation
The medium flows through the valve in the
direction indicated by the arrow. The posi-
tion of the plug (3) determines the cross-sec-
tional area of flow between the plug and the
seat (2).
In the pressureless state (control line not con-
nected and no pressure applied) the valve is
opened by the force of the set point springs
(7).
The downstream pressure p
2
to be controlled
is tapped downstream of the regulator and
transmitted over an external control line to
the control line connection (9) on the actua-
tor housing (6) where it is converted into a
positioning force by the diaphragm plate
with operating diaphragm (5). The dia-
phragm moves the plug over the plug stem
(4) depending on the force of the set point
springs. The spring force can be adjusted at
the set point adjuster (8).
When the force resulting from the down-
stream pressure p
2
rises above the spring
force adjusted at the set point springs, the
valve closes proportionally to the change in
pressure.
p
1
p
2
8
7
6
11
5
4
9
2
3
1
12
Fig. 3:
Type 2405 Pressure Reducing Valve without pressure balancing · K
VS
1.6 to 4 · Flow-to-
open
Содержание 2405 Series
Страница 36: ...36 EB 2520 EN Certificates...