Type EZL Pressure Reducing Regulator for
Low Pressure Applications
W8962
Figure 1. Type EZL Pressure Reducing Regulator
Introduction
Scope of Manual
This manual provides installation, startup,
maintenance and parts ordering information for the
Type EZL pressure reducing regulator. Information on
other equipment used with this regulator is found in
separate manuals.
Product Description
Type EZL regulators are accurate pilot-operated,
pressure balanced and soft seated regulators. They
are designed for use in natural gas distribution
applications such as district regulating stations and
commercial/industrial meter sets. They provide low
differential, smooth, reliable operation, tight shutoff and
long life.
D103091X012
www.fisherregulators.com
Type EZL
The Specications section lists the specications for Type EZL pressure reducing regulator. Factory specications
for specic regulator constructions are stamped on the nameplate fastened to either the main actuator or the pilot
spring case.
Type EZL: Pilot-operated pressure reducing
regulator for low to high outlet pressure
Body Sizes, End Connection Styles and
Pressure Ratings
(1)
See Table 1
Maximum Pressures
(1)
Inlet and Outlet (Design): 285 psig / 19.7 bar
Emergency (Design Casing): 285 psig / 19.7 bar
Operating Differential: 285 psid / 19.7 bar d
Outlet Pressure Ranges
See Table 2
Minimum Differential Pressure
TRIM, PERCENT
OF CAPACITY
100
80
50
30
MINIMUM DIFFERENTIAL FOR
2 in. /
DN 50
2.9 / 0.204
2.9 / 0.204
3.0 / 0.207
3.4 / 0.234
Temperature Capabilities
Standard Elastomers:
-20 to 180°F / -29 to 82°C
High-Temperature Elastomers:
0 to 180°F / -18 to 82°C
(1)
FULL STROKE, psid / bar d
(1)
Options
• Prepiped Pilot Supply
• Travel Indicator
• Integral Type OS2 Slam-shut Device
1. The pressure/temperature limits in this Instruction Manual and any applicable standard or code limitation should not be exceeded.
Table 1. Main Valve Body Sizes, End Connection Styles and Body Ratings
MAIN VALVE BODY SIZEMAIN VALVE BODY MATERIALEND CONNECTION STYLESSTRUCTURAL DESIGN RATING
2, 3 and 4 in. /
DN 50, 80 and 100
1. Structural Design Rating is the rating for the main valve body. The Type EZL complete assembly is limited to 285 psig / 19.7 bar.
2. Available only on 2 in. / DN 50 body
WCC Steel
Cast Iron
(2)
(2)
or SWE
NPT
CL150 RF 290 psig / 20.0 bar
CL300 RF 750 psig / 51.7 bar
CL600 RF or BWE 1500 psig / 103 bar
(2)
NPT
CL125B FF 200 psig / 13.8 bar
CL250B RF 500 psig / 34.5 bar
Figure 2. Type EZL with Type 6352 Pilot and Type P590 Pilot Supply Filter Operational Schematic
Principle of Operation
Single-Pilot Regulator
The pilot-operated Type EZL (Figure 2 or 3) 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 ow 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 satised, 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 orice.
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 compression of the control spring. Adjustment
3
Type EZL
E0959
Type EZL
INLET
PRESSURE
P590 SERIES PILOT
SUPPLY FILTER
TYPE 61L PILOT
E0959
INLET PRESSURE
OUTLET PRESSURE
LOADING PRESSURE
ATMOSPHERIC PRESSURE
SENSE
PRESSURE
LOADING
PRESSURE
TYPE EZL MAIN VALVE
Figure 3. Type EZL with Type 61L Pilot and Type P590 Pilot Supply Filter Operational Schematic
is performed while the regulator is in operation with
the aid of a pressure gauge to monitor downstream
pressure. The shutoff valve downstream of the
regulator must not be completely closed; it is necessary
that a small quantity of gas ows downstream to
allow the outlet side to vent, when it is necessary to
lower the pressure.
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 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 4)
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 conguration, 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.
4
E0948
Type EZL
P590 SERIES
PILOT SUPPLY
FILTER
TYPE 67C PILOT
SUPPLY REGULATOR
Type EZL
TYPE 6352 PILOT
E0948
INLET PRESSURE
OUTLET PRESSURE
LOADING PRESSURE
INTERMEDIATE PRESSURE
ATMOSPHERIC PRESSURE
TYPE 6352 PILOT
TYPE EZL MAIN VALVETYPE EZL MAIN VALVE
Figure 4. Wide-Open Monitoring System Operational Schematic
P590 SERIES PILOT
SUPPLY FILTER
Working Monitoring Regulators (Figure 5)
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
the intermediate pressure must be rated
for full inlet pressure.
Working monitor installations require a Type EZL
main valve with a working pilot and a monitoring pilot
for the upstream regulator and a Type EZL with the
appropriate pilot for the downstream regulator.
Adjustment
Adjusting the monitor regulator is similar to adjusting
the main regulator. Monitor setpoints are set slightly
higher than the main regulator. However, the value
of this difference cannot be determined in advance,
as it depends on the particular characteristics of
each application.
5
Type EZL
E0946
Type EZL
P590 SERIES
PILOT SUPPLY
FILTER
E0946
INLET PRESSURE
OUTLET PRESSURE
LOADING PRESSURE
INTERMEDIATE PRESSURE
ATMOSPHERIC PRESSURE
TYPE 161EBM
MONITOR PILOT
TYPE 6352 PILOT
P590 SERIES PILOT
SUPPLY FILTER
TYPE EZL MAIN VALVETYPE EZL MAIN VALVE
TYPE 6352 PILOT
Figure 5. Working Monitoring System Operational Schematic
Installation
WARNING
!
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
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, be sure
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. To avoid such
injury and damage, install the regulator in
a safe location.
All Installations
A Type EZL 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 ooding
by venting the pilot spring case above the expected
ood level so that the pilot setting can be referenced to
atmospheric pressure.
1. Only personnel qualied through training and
experience should install, operate and maintain a
regulator. Before installation, make sure that there
is no damage to or debris in the regulator. Also,
make sure that all tubing and piping are clean
and unobstructed.
6
Type EZL
Note
When upgrading Fisher® control valves,
such as Types ET, ED and ES make sure
2. Install the regulator so that the ow arrow on the
main valve matches the ow direction of process
uid through the regulator.
3. Apply pipe comlb to the external pipeline threads
before installing a regulator with threaded end
connections. Use gaskets between pipeline and
regulator anges when installing a regulator with
anged end connections. When installing buttweld
end connections, remove trim before welding and
make sure to use approved welding practices.
Use approved piping procedures when installing
the regulator.
WARNING
!
A regulator may vent some gas to the
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. Pilots have a 1/4 in. NPT vent connection in the
spring case. To remotely vent gas from the spring
case, remove the screened vent and connect
1/4 in. / 6.4 mm 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 substances that may clog it.
CAUTION
To avoid freezeup because of pressure
drop and moisture in the gas, use antifreeze practices, such as heating the
supply gas or adding a de-icing agent to
the supply gas.
5. Run a 3/8 in. / 9.5 mm outer diameter or larger pilot
supply line from the upstream pipeline to the lter
inlet as shown in Figure 3, bushing the line down
to t the 1/4 in. threaded NPT lter connection.
Do not make the upstream pipeline connection in
a turbulent area, such as near a nipple, swage or
elbow. If the maximum pilot inlet pressure could
exceed the pilot rating, install a separate reducing
regulator in the pilot supply line. Install a hand valve
in the pilot supply line and provide vent valves
to properly isolate and relieve the pressure from
the regulator.
6. Attach a 1/2 in. / 12 mm piping or tubing
downstream control line to the 1/2 in. threaded NPT
control line connection on the actuator casings.
Connect the other end of the control line to the
pipeline downstream of the regulator. Do not attach
the control line near any elbow, swage, block valve
or any other location that might cause turbulence.
Install a full port ball valve in the control line to
shutoff the control pressure when using the bypass.
7. If a quick acting solenoid is to be installed
downstream of a regulator, the regulator and
solenoid should be located as far apart as practical.
This will maximize the gas piping volume between
the regulator and solenoid and improve the
regulator response to quick changing ow rates.
8. Consult the appropriate instruction manual for
installation of an optional pneumatic or electric
remote control drive unit. For optional remote
pneumatic loading of a 6350 or 61 Series pilot,
make the loading piping connections to the
1/4 in. NPT vent connection.
Wide-Open Monitor Regulator (Figure 4)
1. Follow the procedures in the All Installations
section and then continue with step 2 of
this section.
2. Connect the control line of the wide-open
monitoring regulator to the downstream piping
near the working regulator control line connection.
During normal operation, the wide-open regulator
stands wide-open with the pressure reduction
being taken across the working regulator. Only
in case of working regulator failure does the
wide-open monitoring regulator take control at its
slightly higher setting.
Regardless of which regulator is used as the monitor,
it should be equipped with a pilot supply regulator
set to limit the pilot supply pressure to 10 to 15 psig /
0.69 to 1.0 bar above control pressure. Since the
7
Type EZL
pilot on the monitoring regulator is wide-open during
normal operation, the pilot supply regulator is used
to prevent differential pressure relief valve chatter on
the monitoring regulator pilot.
Working Monitor Regulator (Figure 5)
1. Follow the procedure in the All Installations section
and then continue with step 2 of this section.
2. Attach 3/8 in. / 9.5 mm tubing (for Types 161M and
161EBM) downstream control line to the control line
(sense) connection on the pilot. Connect the other
end of the control line to the pipeline downstream
of the downstream working regulator. Do not attach
the control line near any elbow, swage, block valve
or any other location that might cause turbulence.
3. Apply pilot sense pressure by connecting the
outlet of the monitor pilot to the inlet of the working
monitor pilot.
Startup and Adjustment
Pre-startup Considerations
Each regulator is factory-set for the outlet pressure
specied on the order. If no setting was specied,
outlet pressure was factory-set at the mid-range of
the pilot control spring. Before beginning the startup
procedure in this section, make sure the following
conditions are in effect:
• Block valves isolate the regulator
• Vent valves are closed
• A bypass, if any, is in operation
In all cases, check the control spring setting to make
sure it is correct for the application.
CAUTION
Be sure to slowly introduce pressure
into the system to prevent downstream
overpressure due to potential rapid
pressure increase. Pressure gauges
should always be used to monitor
downstream pressure during startup.
Procedures used in putting this
regulator into operation must be planned
accordingly if the downstream system is
pressurized by another regulator or by a
manual bypass.
Startup
1. Make sure all block valves, vent valves and control
line valve(s) are closed.
2. Back out the pilot adjusting screw(s).
3. Slowly open the valves in the following order:
a. Pilot supply and control line valve(s), if used.
b. Inlet block valves.
4. Crack open the outlet block valve or bypass valve
to allow minimum ow.
5. For a single regulator, set the pilot to the
desired outlet (control) pressure according to
the Pilot Adjustment procedure.
For a wide-open downstream monitor
installation, adjust the upstream working pilot until
intermediate pressure is higher than the desired
setpoint of the monitor pilot. Adjust the downstream
monitoring pilot to the desired monitoring takeover
pressure. Reduce the upstream pilot to the normal
outlet pressure setting.
For a wide-open upstream monitor installation,
adjust the downstream working pilot to a setpoint
higher than the setpoint of the monitor pilot.
Adjust the downstream monitoring pilot to the
desired monitoring takeover pressure. Reduce the
upstream pilot to the normal outlet pressure setting.
For a working monitor installation, adjust the
setpoint of the upstream monitor pilot to the desired
maximum pressure. Adjust the upstream working
pilot to the desired intermediate pressure setting.
Adjust the downstream pilot to a pressure setting
slightly above the upstream monitor pilot pressure
setting. Adjust the upstream monitor pilot to
its desired setpoint. Establish nal desired
downstream pressure by adjusting the downstream
working regulator pilot.
6. After adjusting the pilot(s) to the desired pressure
setting(s), slowly open the downstream block
valve wide-open.
7. Close the bypass valve, if used.
8
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