Brochure

When a building or space requires
precise control and zero valve down
time, these Modulating Magnetic Valves
deliver. Accuracy is unmatched,
particularly in low-flow ranges. This
means energy savings. And these valves
really shine in environments where
climate consistency is critical, such as
research laboratories or micro-
electronic manufacturing facilities.
Siemens has enhanced
valve options using the
unique magnetic design
concept. New models
offer manual setting,
position feedback, and
spring return.
When accuracy counts . . .
. . . specify this
premium, no
maintenance
design.
Optimization in the low opening
range: Siemens Magnetic Valves
control drop by drop.
A: Controlled system response
with a standard valve.
B: Controlled system response
with Siemens Magnetic Valves.
Response time improved by
25%.
T
u
= lag time
T
g
= recovery time
S = degree of difficulty
T
u
s = __
T
g
Linear flow characteristic
Flow is controlled by a large diameter, short-
stroke disc, which forms a lid to the valve seat.
This provides a linear relationship between stroke
and Cv. So the flow characteristic approximates a
straight line in normal modulating ranges. In low
opening ranges, the concave valve characteristic
eliminates problems from sudden increase of
flow on start-up.
Fast positioning speed
The Siemens Magnetic Valve responds to the
control signal so quickly, it can be considered
delay-free in most systems. This improves
control-loop response time and reduces
proportional band error.
Stability
Siemens magnetic actuation provides
exceptional stability in closed loop applications.
The memory characteristics of the magnetic
actuator minimize input-to-output gain as the
control loop nears stability. Unwanted responses
to transient loop disturbances are eliminated.
Resolution is improved.
Position resolution
Digital controllers provide stepped output-signal
changes. This may limit resolution with other valves.
Magnetic actuation positions the valve where needed,
even if between steps, for loop stability. Resolution
exceeds 500:1, even 1000:1 in some models, even with
low-resolution DDC controllers.
Versatility and convenience
Valve and actuator are factory-combined and
precalibrated, saving time in selection, installation and
initial operation. Models accepting a 0-10 VDC
positioning signal meet most needs. Versions for 0-20
VDC are also available. New MXG and MXF models
feature manual setting, position feedback, and spring
return.
Proven and proven again
The Siemens Modulating Magnetic Valves provide
outstanding performance with no periodic maintenance
requirement, as proven by years of research. Reliability
comes from the unique direct-control design — with no
motors, few moving parts, and no metal-to-metal contact
of key parts. Reliability is also acheived through robust
construction, durable materials, and high quality
standards.
Manual Override
Sophisticated
valve electronics
Magnetic
coil
Core
Bellows
Flat valve disc
No surface contact
for key parts
Pre-calibrated valve
and actuator
Unmatched flow
accuracy in low ranges