Actuator Stem Retracts; Mounting Types - Samson 3730 Series Mounting And Operating Instructions

3.3.2

Actuator stem retracts

When the signal pressure is reduced or the
control signal fails, the springs move the ac-
tuator stem upward and open a mounted
globe valve. The valve closes when the signal
pressure is increased enough to overcome
the spring force.

3.4 Mounting types

There are two types of mounting depending
on the valve/actuator combination: mount-
ing using a crossbeam or rods (see Table 3-1
and Table 3-2).
When the actuator is mounted to the valve
using a crossbeam (form B, Fig. 3-5), the ac-
tuator is fastened to the valve bonnet using a
central nut.
When the actuator is mounted using rods
(form C, Fig. 3-6), the actuator is connected
to the valve bonnet using rods. In this case, a
crossbeam is not required for mounting the
actuator. A plate keeps the correct distance
between rods in the 350 cm² version.
Both mounting types are described in the 'In-
stallation' chapter.
Table 3-1: Mounting onto HVAC valves
Actuator area
Type ... Valve Nominal size DN
3214
3214
3260
3260
EB 8313-3 EN
Travel
65 to 100
125 to 250
65 to 80
100 to 150
Design and principle of operation
Fig. 3-5: Form B: mounting using crossbeam
Fig. 3-6: Form C: mounting using rods (in this
example: 350 cm²)
120 cm²
15 mm
Form B
–
Form B
–
350 cm²
30 mm
–
On request
–
Form B
3-5