Emerson FL, MFL Instruction Manual
Instruction Manual
Form 5733
July 2004
FL Series Pressure Reducing Regulators
E0821
E0820
FL Series
Type FL
Figure 1. T ype FL and T ype MFL with T ype SRS Silencer
Introduction
Scope of Manual
This manual provides instructions for installation,
adjustment, maintenance, and parts ordering for the FL
Series regulators.
Description
The FL Series regulators are accurate pilot-operated,
pressure balanced, soft seated regulators designed for
high pressure transmission/city gate, large capacity
distribution systems and power plant feeds. The FL
Series provides smooth, quiet operation, tight shutoff and
long life. The regulator utilizes a main valve actuator , a
Type PRX pressure reducing pilot, and a Type SA/2 pilot
Type MFL with Type SRS Silencer
supply pressure regulator. The T ype PRX pilot uses inlet
pressure reduced by a Type SA/2 supply pressure
regulator, as loading pressure to operate the main valve
actuator. The outlet pressure is sensed through a
control line on the main valve actuator and also on the
Type PRX pilot diaphragm.
Specifications
The Specifications section gives some general specifications for the FL Series regulators. The nameplates
give detailed information for a particular regulator as it
comes from the factory .
D103068X012
www.FISHERregulators.com
FL Series
EPYT
ERUSSERPTELTUO
(GISP,EGNARrab)
GNIRPS
ROLOC
021/XRP
521/XRP
61ot3.7
62ot5.41
44ot32
08ot14
321ot37
)1,1ot5,0(
)
8,1ot1(
)3ot6,1(
)5,5ot8,2(
)5,8ot5(
etihW
wolleY
neerG
eulB
kcalB
012ot611
433ot302
534ot913
906ot124
)5,41ot8(
)3
2ot41(
)03ot22(
)24ot92(
revliS
dloG
munimulA
deR
PA-021/XRP
PA-521/XRP
0611ot534)08ot03(raelC
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
Maximum Emergency (Design Pressure)
1450 psig (100 bar)
Miminum Operating Differential Pressure
7.3 psid (0,5 bar d)
Outlet Pressure Ranges
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
Maximum Inlet and Outlet (Casing) Pressure
(1)
ANSI Class 300 RF: 740 psig (51,0) bar
ANSI Class 600 RF: 1450 psig (100) bar
(1)
1450 psig (100 bar)
1. The pressure/temperature limits in this instruction manual or any applicable standard limitation should not be exceeded.
Pressure Registration
External
Maximum Temperature Capabilities
–20° to 150°F (–29° to 66°C)
(1)
Principle of Operation
The pilot-operated T ype FL (figure 2) uses inlet pressure 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 downstream 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.
2
Adjustment
The adjustment of the regulator is performed by means
of the pilot adjusting screw, which varies the compression of the control spring. Adjustment is performed while
the regulator is in operation with the aid of a test pressure 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
E0827
INLET PRESSURE
OUTLET PRESSURE
LOADING PRESSURE
PILOT SUPPLY PRESSURE
A TMOSPHERIC PRESSURE
FL Series
Figure 2. T ype FL Operational Schematic
keeps the customer on line. Also, testing is relatively
easy and safe. To perform a periodic test on a monitoring regulator, increase the outlet set pressure of the
working regulator and watch the outlet pressure to
determine if the monitoring regulator takes over at the
appropriate outlet pressure.
Wide-Open Monitoring Systems (figure 3)
There are two types of wide-open monitoring systems:
upstream and downstream. The difference between
upstream and downstream monitoring is that the
functions of the regulators are reversed. Systems can
be changed from upstream to downstream monitoring,
and vice-versa, by simply reversing the setpoints of the
two regulators. The decision to use either an upstream
or downstream monitoring system is largely a matter of
personal preference or company policy .
In normal operation of a wide-open configuration, the
working regulator controls the system’s outlet pressure. With a higher outlet pressure setting, the monitor
regulator senses a pressure lower than its setpoint and
tries to increase outlet pressure by going wide-open. If
the working regulator fails, the monitoring regulator
assumes control and holds the outlet pressure at its
outlet pressure setting.
Working Monitoring Regulators (figure 3)
In a working monitoring system, the upstream regulator
requires two pilots and it is always the monitoring
regulator. The additional pilot permits the monitoring
regulator to act as a series regulator to control an
intermediate pressure during normal operation. In this
way , both units are always operating and can be easily
checked for proper operation.
In normal operation, the working regulator controls the
outlet pressure of the system. The monitoring
regulator’s working pilot controls the intermediate
pressure and the monitoring pilot senses the system’s
outlet pressure. If the working regulator fails, the
monitoring pilot will sense the increase in outlet
pressure and take control.
Note
The working regulator must be rated for
the maximum allowable operating
pressure of the system because this will
be its inlet pressure if the monitoring
regulator fails. Also, the outlet pressure
rating of the monitoring pilot, and any
other components that are exposed to
3
FL Series
the intermediate pressure must be rated
for full inlet pressure.
Working monitor installations require a T ype FL main
valve with a Type PRX/120 or PRX/120-AP working pilot
and a T ype PRX/125 or PRX/125-AP monitoring pilot for
the upstream regulator and a Type FL with the appropriate T ype PRX/120 or PRX/120-AP pilot for the downstream regulator. The Type MFL incorporates the
monitor and regulator into one compact unit.
Installation and Startup
Personal injury or equipment damage,
due to bursting of pressure-containing
parts may result if this regulator is overpressured or is installed where service
conditions could exceed the limits given
in the Specification section and on the
appropriate nameplate, or where conditions exceed any rating of the adjacent
piping or piping connections.
To avoid such injury or damage, provide
pressure-relieving or pressure-limiting
devices to prevent service conditions from
exceeding those limits. Also, check that
the installation is in compliance with all
applicable codes and regulations.
Additionally, physical damage to the
regulator could break the pilot off the
main valve, causing personal injury and
property damage due to bursting of
pressure-containing parts. T o avoid such
injury and damage, install the regulator in
a safe location.
Single Pilot Regulator
Installation
A T ype FL regulator bleeds no gas to atmosphere
during normal operation, thus making the regulator
suitable for installation in pits and other enclosed
locations without elaborate venting systems. This
regulator also can be installed in pits subject to
flooding by venting the pilot spring case above the
expected flood level so that the pilot setting can be
referenced to atmospheric pressure.
1. Use qualified personnel when installing, maintaining, or operating this regulator. Inspect the regulator
and the pipeline to be certain both are free of foreign
materials.
2. Install the regulator so that the flow arrow cast on
the main valve matches the flow direction of process
fluid through the regulator.
3. Apply pipe compound to the male pipeline threads
before installing a regulator with screwed end connections. Use gaskets between pipeline and regulator
flanges when installing a regulator with flanged end
connections.
A regulator may vent some gas to the
atmosphere. In hazardous or flammable
gas service, vented gas may accumulate, causing personal injury, death, or
property damage due to bursting of
pressure-retaining parts. Vent a regulator in hazardous gas service to a remote, safe location away from air
intakes or any hazardous location. The
vent line or stack opening must be
protected against condensation or
clogging.
4. A T ype PRX pilot has a 1/4-inch NPT vent connection in the spring case. To remotely vent gas from the
spring case, remove the screened vent, and connect
1/4-inch piping or tubing to the spring case connection.
The piping or tubing should vent to a safe location, have
as few elbows as possible, and have a screened vent
on its exhaust. Install the regulator and any remote
vent piping or tubing so that the vent is protected from
condensation, freezing, or any substance that could
clog it.
5. Connect a pilot supply line from the upstream
piping to the 1/4-inch NPT pilot inlet.
6. Connect a downstream control line to a straight
run of pipe 6 to 10 pipe diameters from the regulator
outlet as shown in figure 3. If such a distance is not
practical, connect the control line away from elbows,
swages, nipples, or any area where abnormal flow
velocities occur.
7. Install a hand valve in the control line.
8. Install the other end of the downstream control
line to the 1/2-inch NPT connection in either side of the
case body.
4
TYPE PRX/120 OR
PRX/120-AP
FL Series
TYPE SA/2
TYPE SA/2
B
L
S
A
Single Pilot System Installation
TYPE PRX/120 OR
PRX/120-AP
B
L
S
A
4 x A
B
A
6 x A
TYPE PRX/120 OR
PRX/120-AP
L
S
A
TYPE SA/2
TYPE SA/2
E0825
TYPE PRX/125 OR
PRX/125-AP
B
4 x A
Upsteam or Downstream Wide-Open Monitoring System Installation
TYPE PRX/120 OR
PRX/120-AP
L
A
B
L
S
S
A
TYPE PRX/120 OR
B
L
S
A
PRX/120-AP
4 x A
6 x A
Working Monitoring System Installation
A
6 x A
A
Figure 3. Installation Drawings
5
Loading...