Emerson Fisher 249VS Instruction Manual

Instruction Manual
Form 5831
November 2007
Cageless 249VS Displacer Sensor
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scope of Manual . . . . . . . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Educational Services
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting the Sensor on the Process Vessel
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing the Displacer and Stem
Replacing the Displacer, Cotter Spring,
Stem End Piece, and Displacer Spud
Replacing the Displacer Rod/Driver Assembly 8
Replacing the Torque Tube
Replacing the Torque Tube Arm and
Changing the Mounting Position
Simulation of Process Conditions for
Calibration of Level-Trol
and Transmitters . . . . . . . . . . . . . . . . . . . . . . .
Parts Ordering . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensor Common Parts

Introduction

Scope of Manual

This instruction manual includes maintenance and
parts ordering information for the cageless 249VS
sensor.
Although a 249VS sensor is usually shipped with an
attached controller or transmitter, this manual does
not include operation, installation, calibration,
maintenance, or parts ordering information for the
controller/transmitter or for the complete unit. For
this information, refer to the appropriate controller/
transmitter instruction manual.
Do not install, operate, or maintain a 249VS sensor
without first D being fully trained and qualified in
valve, actuator and accessory installation, operation
and maintenance, and D carefully reading and
understanding the contents of this manual. If you
have any questions about these instructions, contact
your Emerson Process Managementt sales office.
www.Fisher.com
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R
Controllers
11
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11
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Cageless 249VS Sensor
1
1
1
2
3
6
6
7
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9
W9355
Figure 1. Type 249VS Sensor with DLC3000 Series

Description

The 249VS sensor is designed to measure liquid
level, interface level, or density/specific gravity inside
a process vessel.
A torque tube assembly (figure 2) and displacer
provide an indication of liquid level, interface level, or
density/specific gravity. The torque tube assembly
consists of a hollow torque tube with a shaft welded
inside it at one end and protruding from it at the
other end.
The unconnected end of the tube is sealed by a
gasket and clamped rigidly to the torque tube arm,
permitting the protruding end of the shaft to twist and
therefore transmit rotary motion. This allows the
interior of the torque tube to remain at atmospheric
pressure, thus eliminating packing and the
disadvantages of packing friction.
The displacer always exerts a downward force on
one end of the displacer rod. The other end of the
displacer rod rests on the knife-edge of the driver
bearing. A keyed shaft on the bearing end of the
displacer rod fits into a socket on the outside of the
welded end of the torque tube assembly.
Digital Level Controller