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Fisher
™
VBL Volume Booster
Contents
Introduction
1
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Scope of Manual
1
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Description
1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications
2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Educational Services
2
. . . . . . . . . . . . . . . . . . . . . . . . .
Installation
4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting
4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Connections
5
. . . . . . . . . . . . . . . . . . . . . . . .
Supply Pressure
5
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust Ports
5
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Information
6
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Principle of Operation
7
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Maintenance
8
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Figure 1. Fisher VBL Volume Booster
X0648
Introduction
Scope of Manual
This instruction manual provides installation, operation, maintenance, and parts information for the Fisher VBL
volume booster (figure 1). Refer to separate instruction manuals for information regarding the valve body, actuator,
and other accessories.
Do not install, operate, or maintain a VBL volume booster without being fully trained and qualified in valve, actuator
and accessory installation, operation and maintenance.
To avoid personal injury or property damage it is important to
carefully read, understand, and follow all of the contents of this manual, including all safety cautions and warnings.
If
you have any questions about these instructions, contact your
Emerson sales office
or Local Business Partner before
proceeding.
Description
The VBL volume booster is used in conjunction with a positioner on a throttling control valve to increase stroking
speed. The booster has a fixed deadband (controlled by the seat‐to‐seat dimension of the supply and exhaust plugs)
which is factory set during assembly and testing. In addition, the booster incorporates soft‐seat construction and an
integral bypass restriction to eliminate positioner saturation problems that can occur with volume boosters that do
not have these features. Adjustment of the integral bypass restriction is necessary for system stability. This adjustment
does not affect the deadband of the booster, but does permit the control valve to respond to small input signal
changes from the positioner without sacrificing steady‐state accuracy.
Instruction Manual
D103317X012
VBL Volume Booster
May 2017
