1
Design and principle of
operation
The device combines a Type 2488 Flow Reg-
ulator with a force-locking Type 5824 Actua-
tor or a force-locking Type 5825 Electric Ac-
tuator with fail-safe action. The electric actu-
ator is attached to the regulator by means of
the adapter and allows also the temperature
to be controlled by changing the position of
the orifice (restriction) in response to the con-
trol 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 area re-
leased by the valve plug (3) and the adjust-
able orifice (8.5).
The integral positioning spring (5) determines
the upper differential pressure (0.2 bar).
The high pressure upstream of the orifice is
transmitted to the high-pressure side of the
diaphragm actuator through the control line
(7). The low pressure downstream of the ori-
fice acts on the low-pressure side of the oper-
ating diaphragm (6.1) via a hole in the valve
plug. The differential pressure generated by
the orifice (special differential pressure) is
converted into a positioning force by the op-
erating diaphragm. This force is used to po-
sition the valve plug against the force of the
positioning spring (5).
2
Installation
2.1
Mounting position
Install the regulator in a horizontal pipeline.
Make sure the direction of flow corresponds
with the arrow on the valve body. Place the
electric actuator on top of the valve body.
In cases where the control valve is to be insu-
lated, do not insulate the actuator and cou-
pling nut as well.
Make sure that the permissible ambient tem-
perature is not exceeded especially at the ac-
tuator stem (10.1). If necessary, use an ex-
tension piece (intermediate insulating piece,
order no. 1990-1712). Refer to section 8.
The maximum distance up to the top of the
valve body that can be insulated can be ex-
tended to approx. 25 mm.
Note!
Observe the instructions for the electric actu-
ator specified in EB 5824 EN.
Types 5824-10/-11 and 5825-10/-11 Elec-
tric Actuators with a 7.5 mm rated travel are
used for valves in sizes DN 15 to 25.
Types 5824-20 and 5825-20 Electric Actua-
tors with 12 mm rated travel are required for
valves in nominal sizes DN 32 to 50.
2.2
Strainer
Install a strainer (e.g. SAMSON Type 1 NI)
upstream of the valve to prevent sealing par-
ticles, weld spatter, pipe scale, and other im-
purities carried along by the process medium
from impairing the proper operation, espe-
cially the tight shut-off of the valve.
4
EB 3135-1 EN
Design and principle of operation
