Technical
Instructions
VGD
Series
Double
Valves
Document
Number
CC1N7631us
November
08,
2017
Page
8
Siemens
AG
Building
Technologies
Division
Operation,
continued
7631z53us/1215
Figure
2.
Second
view
of
VGD40.xxxU
flange
models
VGD40.xxxU
double
valves
consist
of
two
valves
in
series.
Each
valve
has
a
double
seat
to
achieve
high
flow
(see
Figure
2
).
Closing
springs:
Each
double
seat
uses
one
pair
of
springs.
The
spring
forces
act
separately
as
closing
forces
on
the
individual
valve
seats.
