Emerson Fisher 249W, Fisher DLC3010 HART Instruction Manual

Instruction Manual

D102803X012

249W Sensor

December 2012

Fisherr 249W Cageless Wafer Style Displacer
Sensor

Contents

Introduction 1.................................

Scope of Manual 1.............................

Description 2.................................

Type Number Description 3.....................

Educational Services 3.........................

Installation 4..................................

Installation on Top of Vessel 5...................

Installation with Displacer Cage

on Side of Vessel 5..........................

Mounting the Sensor on the Process

Vessel or Displacer Cage 9....................

Maintenance 11................................

Removing the Displacer and Stem 12.............

Replacing the Displacer, Cotter Spring,

Stem End Piece, and Displacer Spud 13.........

Replacing the Displacer Rod/Driver

Assembly 13...............................

Replacing the Torque Tube 14...................

Changing the Mounting from Left‐Hand to

Right‐Hand, or Vice Versa 16.................

Simulation of Process Conditions for Calibration

of Fisher Level Controllers and Transmitters 16......

Related Documents 17..........................

Parts Ordering 17...............................

Determining Displacer Stem Length 17...........

Parts List 18...................................

Figure 1. Fisher 249W Sensor with FIELDVUE™
DLC3010/DLC3020f Digital Level Controller

W8231

Introduction

Scope of Manual

This instruction manual includes maintenance, and parts ordering information for the 249W cageless wafer style
sensor.

Although the sensor is usually shipped with attached controller or transmitter, as shown in figure 1, 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.

www.Fisher.com

249W Sensor

December 2012

Instruction Manual

D102803X012

Do not install, operate, or maintain a 249W sensor and the attached controller or transmitter 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

Process Management sales office before proceeding.

Description

The 249W 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.

Figure 2. Typical Cageless Displacer

TORQUE TUBE

W1800‐1

KNIFE EDGE
BEARING

DISPLACER ROD

DISPLACER

W8325

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 fits into a socket on the
outside of the welded end of the torque tube assembly.

A change in liquid level, interface level, or density/specific gravity buoys up the displacer by a force equal to the weight
of the liquid displaced. Corresponding vertical movement of the displacer results in angular movement of the displacer
rod around the knife edge. Since the torque tube assembly is a torsional spring which supports the displacer and
determines the amount of movement of the displacer rod for a given displacement change, it will twist a specific
amount for each increment of buoyancy change. This rotation is brought through the torque tube arm by the
protruding rotary shaft. A controller or transmitter attached to the end of the rotary shaft converts the rotary motion
into varying pneumatic or electric signals. Figure 3 shows how the controller or transmitter mounts on the torque tube
arm.

Unless otherwise noted, all NACE references are to NACE MR0175-2002.

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Instruction Manual

D102803X012

Figure 3. Torque Tube Arm Exploded View Showing Controller or Transmitter Mounting

249W Sensor

December 2012

CONTROLLER OR TRANSMITTER
(DLC3010/DLC3020f
SHOWN)

GE51212

RETAINING
FLANGE

ROTARY SHAFT

POSITIONING
PLATE

MOUNTING HOLES ACCEPT
FOUR STUDS OR CAP SCREWS
DEPENDING ON CONTROLLER OR
TRANSMITTER

OUTER
TUBE END

GASKET

HEX NUTS OR CAP
SCREWS DEPENDING ON
CONTROLLER OR TRANSMITTER

TORQUE
TUBE ARM

Type Number Description

D 249W—NPS 3 or 4, CL150, CL300, or CL600 steel cageless sensor.

The Parts List section shows some 249W constructions, standard displacer lengths, and standard materials, and table 1
contains materials of construction. However, 249W parts are available in a wide variety of materials of construction,
part dimensions, and other specifications. Contact your Emerson Process Management sales office for assistance in
selection of specific materials, dimensions, and specifications.

Table 1. Materials of Construction

Part Standard Material Other Materials

Wafer Body and Torque Tube Arm WCC (NACE MR0175 compliant) 316 Stainless Steel

Displacer 304 Stainless Steel 316 Stainless Steel, N10276, N04400, Plastic, and Special Alloys

Displacer Stem, Driver Bearing,
Displacer Rod and Driver

Torque Tube N05500

Bolting

Torque Tube Arm Gasket and
Torque Tube End Gasket

1. N05500 is not recommended for spring applications above 232_C (450_F). Contact your Emerson Process Management sales office or application engineer if temperatures exceeding this
limit are required.

316 Stainless Steel N10276, N04400, other Austenitic Stainless Steels, and Special Alloys

(1)

NCF coated steel grade B7 studs or

cap screws and grade 2H nuts

Graphite/Stainless Steel N04400/PTFE

316 Stainless Steel, N06600, N10276

Steel Grade B7M or M8M studs and grade 2M nuts

Educational Services

For information on available courses for 249W level sensors, as well as a variety of other products, contact:

Emerson Process Management
Educational Services, Registration
P.O. Box 190; 301 S. 1st Ave.
Marshalltown, IA 50158-2823
Phone: [phone] or
Phone: [phone]
FAX: [phone]
e‐mail: [e-mail]

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249W Sensor

December 2012

Instruction Manual

D102803X012

Installation

WARNING

To avoid personal injury or property damage resulting from the sudden release of pressure:

D Always wear protective clothing, gloves, and eyewear when performing any installation operations to avoid personal

injury.

D Check with your process or safety engineer for any additional measures that must be taken to protect against process

media.

D If installing into an existing application, also refer to the WARNING at the beginning of the Maintenance section of this

instruction manual.

The 249W sensor can be installed directly on the vessel as shown in figure 4. It also can be installed in a user fabricated
cage mounted on the side of the vessel as shown in figure 5. The sensor mounts on the top of the vessel or in the
displacer cage using an NPS 3 raised face flange with the NPS 3 249W wafer body, or an NPS 4 raised‐face flange with
the NPS 4 249W wafer body.

Figure 4. Fisher 249W Sensor Top Mounted on Vessel

249W WAFER BODY

NPS 3 OR 4 RF FLANGE

DISPLACER

STILLWELL

NOTE:
1 STILLWELL REQUIRED AROUND DISPLACER IF THE FLUID IS IN A STATE
OF CONTINUOUS AGITATION

W8266

1

4

Instruction Manual

D102803X012

Figure 5. Fisher 249W Sensor Cage‐Mounted on Side of Vessel

249W Sensor

December 2012

W8267

CAGE WITH TOP AND BOTTOM CONNECTIONS

W8268

CAGE WITH SIDE CONNECTIONS

Installation on Top of Vessel

Note

If a stillwell is used, install it plumb so that the displacer does not touch the wall of the stillwell. If the displacer touches the wall,
the unit will transmit an erroneous output signal.

Because the displacer hangs inside the vessel, provide a stillwell around the displacer if the fluid is in a state of
continuous agitation to avoid excessive turbulence around the displacer.

To attach the sensor body to the vessel requires a flanged connection on the vessel as shown in figure 4. For interface
or fluid level applications, install a gauge glass on the vessel.

Installation with Displacer Cage on Side of Vessel

Note

Install the cage so that it is plumb; the displacer must not touch the cage wall. If the displacer touches the cage wall, the unit will
transmit an erroneous output signal.

Figure 5 shows the 249W sensor mounted on the side of a vessel using a displacer cage. Figure 6 provides the 249W
dimensions required to fabricate a cage. Figure 7 provides overall envelope dimensions for a 249W sensor and
DLC3010/DLC3020f controller, and figure 8 provides overall envelope dimensions for a 249W and 2500 controller or
transmitter.

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249W Sensor

December 2012

Figure 6. Typical Cage Connections

1

G

Instruction Manual

D102803X012

G

1

CAGE WITH TOP AND

STYLE 1

LOWER SIDE VESSEL CONNECTIONS

GE06686

CAGE WITH TOP AND

BOTTOM VESSEL CONNECTIONS

GE06685

NPS 3 OR 4 CL150, CL300, OR
CL600 FLANGE

1

1

G

G

356 mm

(14‐INCHES)

STYLE 3

CAGE WITH UPPER AND

LOWER SIDE VESSEL CONNECTIONS

NOTES:

GE06687

1 DIMENSION G IS CUSTOMER SPECIFIED

CAGE WITH UPPER SIDE AND

BOTTOM VESSEL CONNECTIONS

GE06688

2. VESSEL CONNECTIONS ARE EITHER NPS 1‐1/2 OR 2 CL150, CL300 OR CL600 FLANGES.
(VESSEL ENDS CAN BE ALSO SCREWED OR SOCKET WELDED CONNECTIONS)

3. DISPLACER LENGTH ILLUSTRATED IS 14‐INCHES

4. CONNECTIONS SHOWN ILLUSTRATE THE DLC3010/DLC3020f. CONNECTIONS ARE ALSO APPLICABLE TO THE 2500

STYLE 2

STYLE 4

6