Shutdown - Fisher CS403 Instruction Manual

CS400 Series
The range of allowable pressure settings
is stamped on the nameplate. If the
required setting is not within this range,
substitute the correct spring (as shown
in Table 5). If the spring is changed,
change the nameplate to indicate the
new pressure range.
A pressure gauge should always be used to monitor
downstream pressure while adjustments are being made.
1. Remove the closing cap (key 60, Figure 8).
2. To increase the outlet setting, turn the adjusting
screw (key 65, Figure 8) clockwise. To
decrease the outlet setting, turn the adjusting
screw counterclockwise.
3. Replace the closing cap.
CS400 Series with Integral Monitor Module
When adjusting the Primary Regulator and Integral
Monitor for operation, ensure that the pressure
differences between the Primary Regulator and the
integral monitor shown in Table 6 are observed. For
example, if the Primary Regulator setpoint is set at
7 in. w.c. / 17 mbar, than the Integral Monitor should
be set at a minimum of 14 in. w.c. / 35 mbar or higher.
To test the Integral Monitor operation, the Primary
regulator setpoint must be adjusted above the Integral
Monitor's setpoint to simulate a failure of the primary
regulator. If the spring range of the Primary Regulator
is sufficiently high, it can simply be adjusted above the
Integral Monitor's setpoint by following step 2 above.
Otherwise, a different spring with a setpoint higher
than the Integral Monitor's setpoint must be installed to
check the operation of the Integral Monitor.
CS400 Series with Slam-shut Module
When adjusting the primary regulator and slam shut
for operation, reference Tables 7 and 8 for the OPSO
and UPSO setpoints of the slam shut for the given
regulator spring ranges.
WARNING
!
In the case of a downstream line break,
numerous factors affect the capability to
evacuate gas from the pipeline. These
factors include the distance of pipe to the
break, the diameter of the pipe, size of the
break and the number of restrictions, such
as valves, elbows and bends, downstream
12
of the regulator and/or slam-shut device.
Due to these factors additional protections
should be installed to stop flow in the
event of a line break.
Equipment installed downstream the
Type VSX slam shut device can be
damaged if the following procedure
for resetting the Type VSX slam shut
device is not followed. This equipment
includes the integral Type VSX
regulator configurations.
Step 1:
To properly reset the Type VSX slam shut after it
has been tripped to the closed position, a flat-head
screwdriver must be inserted into the position shown
in Figure 8 on the backside of the reset button (key 30,
Figure 8).
Step 2:
The screwdriver should be slowly rotated to gradually
pull the reset button (key 30) away from the Type VSX
device. This slow movement allows for a slow bleed
of the pressure across the Type VSX slam shut's disk
and seat area. The operator should be able to hear the
pressure bleeding through the system.
Step 3:
When the pressure has equalized and the air bleeding
sound has dissipated, the reset button (key 30)
should be pulled completely away from the Type VSX
slam shut device by hand until the internal shut-off
mechanism has been re-latched.
Step 4:
Once the operator feels the click of the re-latch
occurring, the reset button (key 30) should be pushed
completely back into its original position.

Shutdown

Installation arrangements may vary, but in any
installation it is important that the valves be opened
or closed slowly and that the outlet pressure be
vented before venting inlet pressure to prevent
damage caused by reverse pressurization of the
regulator. The steps in the following page apply to the
typical installation as indicated.
CAUTION