The Model 120 has a wide range of applications: anywhere the flow rate
must be controlled or limited.
Typical examples include:
●Pump systems
●Fuel metering systems

SERIES FEATURES

●Controls or limits flow to a predetermined rate
●Built-in orifice plate for sensing flow rate
●Extra-sensitive differential pilot
●Flow rate is adjustable with single screw
●Adjustable response speed
●Can be maintained without removal from the line

●Factory tested and can be pre-set
to your requirements

OPERATION
The normally open, spring loaded pilot, sensing
the differential across the integral orifice
plate which is located in the valve inlet flange,
responds to changes in differential and causes
the main valve to do the same. Increased differential(flow rate) works to close the pilot and
main valve, whereas decreased differential
works to open them. The net result is a constant
modulating action of the pilot and main
valve to hold the differential, hence the flow
rate, constant. The pilot system is equipped
with a needle valve that fine tunes the valve's
response to the system variables.
COMPONENTS
The Model 120 consists of the following components,arranged as shown on the schematic diagram:
1.) Model 65 Basic Control Valve
2.) Orifice Plate
3.) Model 2450 Rate of Flow Control Pilot
4.) Model 126 Ejector
5.) Model 141-2 Needle Valve
6.) Model 123 Inline Strainer
7.) Model 155L Visual Indicator (optional)

SIZING
The following chart states the minimum and
maximum flow rate with standard bore orifice
plate, based on a fluid specific gravity of 0.8.
This means the valve can be adjusted to control
within the ranges shown. Lower flow ranges are
possible through the use of smaller orifice plate
bore and all ranges are adjustable within a 4:1
ratio (high to low flow). Consult the factory for
assistance.

SCHEMATIC

RECOMMENDED INSTALLATION
Install the valve with adequate space above and around the valve to facilitate servicing.
Refer to the Dimension Table.
Valve should be installed with the bonnet (cover) at the top, particularly 8" and larger
valves, and any valve with a limit switch.
Shut-off valves should be installed upstream and downstream of the control valve.
These are used to isolate the valve during start-up and maintenance.
In order to properly set the flow rate, a meter, or some other means of measuring flow,should be installed in series with the control valve.

MAX. PRESSURE
(The pressures listed here are maximum working
pressures at 100°F)