FL Series
2
1. The pressure/temperature limits in this instruction manual or any applicable standard limitation should not be exceeded.
Specifications
Available Configurations
FL: Pilot-operated pressure reducing regulator
for medium to high outlet pressures
MFL: Monitor and regulator combined into a single
unit for overpressure protection
Body Sizes
FL and MFL:
1, 1-1/2, 2, 2-1/2, 3, 4, and 6-inch (DN 25, 40, 50, 65,
80, 100, and 150) (6-inch for FL only)
FL and MFL with SRS Silencer (inlet x outlet):
1 x 4, 1-1/2 x 6, 2 x 6, 2-1/2 x 8, 3 x 10, 4 x 10, and
6 x 12-inch (DN 25 x 100, 40 x 150, 50 x 150,
65 x 200, 80 x 250, 100 x 250, and 150 x 300)
(6 x 12-inch for FL only)
Main Valve End Connection Style and Pressure
Ratings
(1)
ANSI Class 300 RF: 740 psig (51,0) bar
ANSI Class 600 RF: 1450 psig (100) bar
Maximum Inlet and Outlet (Casing) Pressure
(1)
1450 psig (100 bar)
Maximum Emergency (Design Pressure)
1450 psig (100 bar)
Miminum Operating Differential Pressure
7.3 psid (0,5 bar d)
Outlet Pressure Ranges
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Pressure Registration
External
Maximum Temperature Capabilities
(1)
–20° to 150°F (–29° to 66°C)
Principle of Operation
The pilot-operated Type FL (figure 2) uses inlet pres-
sure as the operating medium, which is reduced
through pilot operation to load the actuator diaphragm.
Outlet or downstream pressure opposes loading
pressure in the actuator and also opposes the pilot
control spring.
When outlet pressure drops below the setting of the
pilot control spring, pilot control spring force on the pilot
diaphragm thus opens the pilot valve plug, providing
additional loading pressure to the actuator diaphragm.
This diaphragm loading pressure opens the main valve
plug, supplying the required flow to the downstream
system. Any excess loading pressure on the actuator
diaphragm escapes downstream through the bleed
restriction in the pilot.
When the gas demand in the downstream system has
been satisfied, the outlet pressure increases. The
increased pressure is transmitted through the down-
stream control line and acts on the pilot diaphragm. This
pressure exceeds the pilot spring setting and moves the
diaphragm, closing the orifice. The loading pressure
acting on the main diaphragm bleeds to the downstream
system through a bleed restriction in the pilot.
Adjustment
The adjustment of the regulator is performed by means
of the pilot adjusting screw, which varies the compres-
sion of the control spring. Adjustment is performed while
the regulator is in operation with the aid of a test pres-
sure gauge of suitable range or of a water column. The
shutoff valve downstream of the regulator must not be
completely closed; it is necessary that a small quantity
of gas flows downstream to allow the outlet side to vent
down, when it is necessary to lower the pressure.
Loosen the locknut and turn the adjusting screw slowly to
adjust outlet pressure. Use a pressure gauge to check
the outlet pressure until the desired pressure is reached.
Monitoring Systems
Monitoring regulation is overpressure protection by
containment, therefore, there is no relief valve to vent to
the atmosphere. When the working regulator fails to
control the pressure, a monitor regulator installed in
series, which has been sensing the downstream and
control pressure, goes into operation to maintain the
downstream pressure at a slightly higher than normal
pressure. During an overpressure situation, monitoring
Содержание FL
Страница 12: ...FL Series 12 Figure 4 FL Assembly ...
