Instruction Manual
D102588X012
January 2018
Type 289RC Exhaust Booster
Type 289RC
Figure 1. Type 289RC Exhaust Booster
Introduction
Scope of the Manual
This manual describes the principles of operation and
provides installation instructions and a parts list for the
Type 289RC exhaust booster.
Product Description
The Type 289RC high-capacity exhaust booster
provides “release control (RC)” control pressure
to actuators, other pneumatic devices, and related
systems that require rapid response, such as surge
valves or recycle valves on compressors. This exhaust
booster is normally used on control valve actuators
to speed up the proportional operation of a control
valve in response to sudden pressure changes from
pneumatic output devices, such as solenoid valves
or pneumatic instruments. By carefully matching
the instrument and actuator performance with the
bypass valve adjustment, the Type 289RC reduces
overshoot and related problems while allowing very
fast positioning response to system requirements (i.e.,
compressor surge control). The one-way throttling
action offers superior control with exceptional stability
and the specially designed boosting system provides
high ow rates with minimum buildup.
Type 289RC
Specications
Specications for the Type 289RC exhaust booster are listed on page 2. Specications for a given exhaust
booster as it originally comes from the factory are stamped on the nameplate.
Body Size
1 NPT
Inlet and Outlet Connections
Signal: 1/8 NPT (standard)
Outlet: 1 NPT
Maximum Pressure
(1)
Inlet: Connect to the outlet via a bypass valve,
adjustable from 0 to 0.3 Cv. (Piping is normally
congured by the customer.) See Figure 3.
(1)
Dead Band
0.5 psid / 0.034 bar d pressure across the
bypass valve
Maximum Exhaust Flow Capacity
Cv = 22. System capacity limited by the
smallest restriction between the exhaust valve
and pressure source (actuator).
Temperature Capabilities
-20 to 180°F / -29 to 82°C
100 psig / 6.9 bar
Approximate Weight
Input to Output Pressure Ratio
4 lbs / 2 kg
Fixed at 1 to 1
1. The pressure/temperature limits in this Instruction Manual and any applicable standard or code limitation should not be exceeded.
Principle of Operation
bypass valve, the further the exhaust booster will
open. The booster exhaust valve closes as the
The Type 289RC 1 NPT outlet port is connected
directly to a spring return actuator and the 1/8 NPT
pressure difference between the instrument and
actuator decreases.
inlet connection on the spring case is connected to
the controlling instrument (I/P transducer, controller,
positioner, etc.). The assembly of the Type 289RC to a
control valve requires the inlet and outlet chambers be
connected via a bypass valve. The bypass valve should
be installed between the two 1/8 NPT connections on
the Type 289RC or any other convenient location per
the customer’s preference. The Type 289RC exhaust
booster has a factory set opening threshold of 0.5 psid /
0.03 bar d. The adjustment screw in the booster body
is not eld adjustable. The bypass valve is adjusted
Installation
The schematic on page 3 (Figure 2) shows the typical
Type 289RC installation. Connect the instrument
supply to the 1/8 NPT spring case inlet and the
actuator to the 1 NPT side port outlet. The inlet and
outlet must be connected via an adjustable bypass
valve. Flow through the exhaust valve must be in the
same direction as the ow arrow on the body.
on the control valve system to account for differences
in various instrument and actuator performance
characteristics. Once adjusted, the control valve
action is as described in the following paragraph.
As the output pressure of the instrument increases the
actuator moves the valve normally since the exhaust
booster cannot be actuated with an increasing signal.
Mounting is recommended with the
outlet exhaust connection pointing
down. If it is necessary to pipe this
outlet away from the area, remove the
outlet screen.
When the output pressure of the instrument decreases
the actuator will move the valve until the rate of
change of the output pressure develops 0.5 psid /
0.034 bar d across the bypass valve. When this
occurs, the pressure differential in the Type 289RC
causes the exhaust booster valve to begin opening
and begin reducing the pressure in the actuator. The
greater the differential pressure develops across the
Protect the outlet exhaust connection
against the entrance of rain, snow,
insects or any other foreign material
that may block the outlet or affect the
opening and closing of the valve.
(1)
Note
CAUTION
2
METERED FLOW
FREE FLOW
ADJUSTABLE
BYPASS VALVE
(0 TO 0.3 C
Type 289RC
)
V
TYPE 289RC
INSTRUMENT SUPPLY
45 TO 125 psig /
3.1 TO 8.6 bar
A7208
I/P
4 TO 20 mA
Figure 2. Typical Type 289RC Exhaust Booster and Control Valve Installation
3
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