Principle Of Operation; Installation And Overpressure Protection - Emerson Fisher VS100 Series Instruction Manual

TS
VS121 VS122
-20/60°C
-20/66°C
VS111 VS112
SHUTOFF
R
TS
PS
PS
IS 6 bar
DN
DS 20 bar
PN
See Table 6
Figure 2. PED VS100 Series Label

Principle of Operation

The pressure in the zone to be protected (generally
the pipeline on the outlet side of the pressure
regulator and situated after the slam-shut device
(see Figures 5 and 7) activates the VSX4 and
VSX8 Series controller.
The pressure measuring element of the
VSX4 and VSX8 Series controller consists of a
diaphragm that senses downstream pressure. The
downstream pressure is controlled by the regulator
(Figure 7). The top side of the VSX4 and VSX8 Series
diaphragm encounters the force imposed by the
overpressure shut-off spring and underpressure
shut-off spring.
When the downstream pressure increases above the
overpressure shut-off (OPSO) setting, the diaphragm
moves up.
When the downstream pressure decreases below the
underpressure shut-off (UPSO) setting, the diaphragm
moves down.
Both of these actions result in the rotation of the cam
and the release of the reset pin.
The valve plug spring moves the valve plug against
the regulator port, stopping the flow of gas.
Before opening the valve plug, an equal pressure
balance on inlet and outlet sides is required.
TEMPERATURE
CLASS
2
/
Manufacturing site
SERIAL NO. LOC
527 Manufacturing date
TEMP
DOM JJ MM AN
CLASS
FLUID
SEAT 1 CAT IV
GROUP
BODY
MATL
TYPE
No de Série
SERIAL No.
Utilisation
INTENDED USE
Figure 4. Nameplate for explosive atmosphere if ATEX assembled
527 = Cluj
JJ MM AN
O 19
Steel (WCC)
Iron (GS)
IS
PS 6 bar P 6 bar
umax
DS
PS 20 bar P 16 bar
umax
Figure 3. EN 14382 VSX4 and VSX8 Series Label
FRANCEL SAS
Chartres FRANCE
An
YEAR
Refer to the VSX4 and VSX8 Series Instruction
Manual, Form 5867. Using the reset button, activate
the internal bypass, then rearm the valve plug in
accordance with the Manual Reset Procedure.
Rearming and pressure balancing are achieved at the
same time.
installation and
Overpressure Protection
Personal injury or system damage
may result if this slam-shut device
is installed, without appropriate
overpressure protection, where service
conditions could exceed the limits
given on the Specifications section and
slam- shut device nameplate.
all vents should be kept open to permit
free flow of gas to the atmosphere.
Protect openings against entrance of
rain, snow, insects or any other foreign
material that may plug the vent or vent
line. When installing outdoors, point the
spring case vent of the regulator and of
the slam-shut device downward to allow
condensate to drain. This minimizes the
VS100 Series
VSX4L VSX4H
VSX8L VSX8H
PSD 6 bar
Pressure range following
PSD 6 bar
service condition
2 G T
Warning
!
IS
6 bar
DS 16 bar
LP
1.5 bar
HP 5.5 bar
A Min, Min and
Max installation
B Max installation
only
7