Fisher Instruction Manual: Fisher L2sj Low Emission Liquid Level Controller Manuals & Guides

Instruction Manual

D103216X012

L2sj Controller

June 2022

Fisher™ L2sj Low Emission Liquid Level Controller

Contents

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

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

Description 3.................................

Specifications 3...............................

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

Principle of Operation 4.........................

Installation 5..................................

Attaching Vertical Displacer 6...................

Mounting the Controller to the Vessel 6...........

Attaching Horizontal Displacer 6.................

Supply Pressure Connections 7..................

Vent 7.......................................

Set‐up and Adjustments 7.......................

Dry Displacer Setup 7..........................

Wet Displacer Adjustments 9...................

Maintenance 9.................................

Removing the Controller From the Sensor 10........

Replacing the Sensor O‐Rings 10.................

Disassembly 10............................

Assembly 10..............................

Replacing the Controller Relay 12................

Replacing the Controller Supply Filter 12..........

Parts Ordering 12...............................

Figure 1. Fisher L2sj Liquid Level Controller

W9331

Parts Kits 13...................................

Parts List 13...................................

Controller 13.................................

Sensor 14....................................

Introduction

Scope of Manual

This instruction manual includes installation, adjustment, maintenance, and parts ordering information for the Fisher
L2sj low emission liquid level controller.

Do not install, operate or maintain a L2sj low emission liquid level controller 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
contents of this manual, including all safety cautions and warnings. If you have any questions about

these instructions, contact your Emerson sales office

www.Fisher.com

before proceeding.

L2sj Controller

June 2022

Table 1. Specifications

Instruction Manual

D103216X012

Available Configuration

Controller: On‐Off / Direct Acting
Sensor: Displacer‐type liquid level sensor for

mounting to side of vessel.

Input Signal

Liquid Level (gas over liquid)

Liquid Level Span

(1)

See table 2

Minimum Specific Gravity

3 x 6 inch displacer: 0.6
1-7/8 x 12 inch displacer: 0.75

Output Signal

Control: Pneumatic On‐Off
Range: 0 psi (off) or full supply pressure (on)
Action: Direct acting (increasing level increases

output signal)

Supply Pressure Requirements

Any desired pressure between 0.34 and 2.4 bar
(5 and 35 psig).

Supply Medium

Air or natural gas

(2)

Displacer Size

3

J 48 x 305 mm, 541 cm

3)(4)

33 in
42 in

or J 76 x 152 mm, 688 cm3 (3 x 6 inches,

3)(5)

Maximum Sensor Working Pressure

(1‐7/8 x 12 inches,

(6)

PVC Displacer: Consistent with CL1500 pressure
temperature ratings per ASME B16.34 up to
maximum pressure of 258 bar (3750 psig)
For PED (97/23/EC) maximum pressure limited to 200
bar (2900 psig)

S31603 SST Displacer: CL600 pressure temperature
ratings per ASME B16.34 up to maximum pressure of

99.3 bar (1440 psig)

Note: For slip‐on flange connection, maximum sensor
working pressure must be consistent with the flange
ratings

Sensor Temperature Limits

(6)

PVC Displacer: -18 to 71_C (0 to 160_F)
S31603 SST Displacer: -40 to 204_C (-40 to 400_F)

Operative Ambient Temperature Limits

(6)

Controller: -29 to 71_C (-20 to 160_F)

Standard Supply, and Output Pressure Gauge
Indications

Triple scale gauges in 0 to 60 psig / 0 to 0.4 MPa / 0 to

4.0 bar

Steady‐State Air Consumption

(3)

t0.01 normal m3/hr (t0.3 scfh) at 1.4 bar (20 psig)
supply pressure

Sensor to Vessel Connection

J 2 NPT threaded or J NPS 2 CL150 through 1500

slip‐on flange connection

Controller Connections

Supply: 1/4 NPT internal located on the bottom of the
case
Output: 1/4 NPT internal located on the top of the
case

Case Vent: 1/4 NPT internal with vent screen
assembly located on the back of the case

2

Hazardous Area Classification

Complies with the requirements of ATEX Group II
Category 2 Gas and Dust

EX h IIC Tx Gb
EX h IIIC Tx Db

Maximum surface temperature (Tx) depends on
operating conditions

Gas: T6
Dust: T71

Meets Customs Union technical regulation TP TC
012/2011 for Groups II/III Category 2 equipment

II Gb c T*X
III Db c T*X

-continued-

Instruction Manual

D103216X012

Table 1. Specifications (continued)

L2sj Controller

June 2022

Canadian Registration

The L2sj utilizes the same sensor unit pressure
component as the L2 pneumatic controller version.
Refer to the L2 CRN which is deemed applicable to
the L2sj.

Declaration of SEP

Fisher Controls International LLC declares this
product to be in compliance with Article 3 paragraph

NOTE: Specialized instrument terms are defined in ANSI/ISA Standard 51.1 - Process Instrument Terminology.

1. Level change required for full change in output signal.

2. This product can be used with natural gas as the supply medium.

3. Normal m

4. Supplied with 6 inch extension.

5. Supplied with 3 inch extension.

6. The pressure and temperature limits in this document and any applicable standard or code limitation should not be exceeded.

3

/hr—Normal cubic meters per hour (0_C and 1.01325 bar, absolute) Scfh—Standard cubic feet per hour (60_F and 14.7 psia).

product to be in compliance with Article 4 paragraph
3 of the PED Directive 2014/68/EU. It was designed
and manufactured in accordance with Sound
Engineering Practice (SEP) and cannot bear the CE
marking related to PED compliance.

However, the product may bear the CE marking to
indicate compliance with other applicable European
Community Directives.

Table 2. Liquid Level Span

SENSOR

Vertical Displacer Span, mm (inch)

1-7/8 x 12 inch Displacer with 6 inch extension n/a 135 (5.3) 102 (4.0)

3 x 6 inch Displacer 3 inch extension 57 (2.25) 46 (1.8) 34 (1.35)

Horizontal Displacer

3 x 6 inch Displacer with 3 inch extension 22 (0.85) 17 (0.67) 13 (0.5)

Notes

1. Level change required for full change in output signal.

2. Span adjuster set for maximum sensitivity.

3. 1.4 bar (20 psig) supply pressure.

4. For vessels with fast dump cycles, actual liquid span will be larger

SPECIFIC GRAVITY OF LIQUID

0.6 0.75 1

Span, mm (inch)

Description

The rugged L2sj low emission liquid level controller uses a displacer type sensor (see figure 1) to detect liquid level.

The controller features a rugged, metal‐seated relay with proportional and integral action. The device delivers a
pneumatic output signal to a control/dump valve.

Specifications

Specifications for the controller and sensor are listed in table 1.

Educational Services

Emerson Automation Solutions
Educational Services - Registration
Phone: [phone]
E-mail: [e-mail]
emerson.com/mytraining

3

L2sj Controller

June 2022

Instruction Manual

D103216X012

Principle of Operation

The operation of the L2sj controller in combination with the sensor is based on the Archimedes Principle, which states
that a body immersed in a liquid will be buoyed up by a force equal to the weight of the liquid displaced. The buoyant
force and resultant movement of the displacer in the liquid is transmitted to the controller which delivers a pneumatic
signal to a control valve.

Figure 2 shows a simple schematic of the controller and sensor. In its normal position, the counterclockwise moment
due to the weight of the displacer about pivot point O is balanced by the sum of the clockwise zero spring moment
and the counterclockwise relay force moment applied through lever A to the displacer rod. The weight of the displacer
decreases when the liquid level increases and the subsequent buoyant force increases causing a force imbalance
between the zero spring, relay, and displacer forces. This force imbalance is transmitted to the relay by levers A and B.
The relay compensates for the force imbalance by converting it to a pressure output to a control/dump valve and
bringing the forces back into equilibrium.

Figure 2. Operational Schematic

LEVER B

DISPLACER ROD

DISPLACER

PROPORTIONAL BAND
ADJUSTMENT

PIVOT
POINT O

RELAY

ZERO SPRING

LEVER A

4

Instruction Manual

D103216X012

L2sj Controller

June 2022

Installation

WARNING

D Wear protective clothing, gloves, and eyewear whenever possible when performing any installation operations to

avoid personal injury or property damage.

D To avoid personal injury or property damage caused by the sudden release of process fluid, be certain the service

conditions do not exceed the sensor pressure limits. Use pressure‐limiting or pressure‐relieving devices to prevent
service conditions from exceeding these limits.

D Personal injury or property damage may result from fire or explosion if natural gas is used as the supply medium and

preventive measures are not taken. Preventive measures may include, but are not limited to, one or more of the
following: Remote venting of the unit, re‐evaluating the hazardous area classification, ensuring adequate ventilation,
and the removal of any ignition sources. For information on remote venting of this controller, refer to page 7.

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

this instruction manual.

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

media.

NOTICE

Do not use sealing tape on pneumatic connections. This instrument contains small passages that may become obstructed
by detached sealing tape. Thread sealant paste should be used to seal and lubricate pneumatic threaded connections.

NOTICE

If the L2sj low emission liquid level controller is installed on a vessel that is to be shipped to a different location (e.g. skid
mounted units), remove the displacer and displacer rod extensions before shipment. Failure to do so could result in
damage to the displacer rod due to vibration and impact loading during shipment. After the vessel is installed at its final
location, reassemble the displacer and displacer rod extension.

1. Be sure there are no obstructions inside the vessel that will interfere with displacer installation or operation.

2. Provide the appropriate connection in the vessel wall to match the sensor connection. Locate the vessel connection
so that the displacer will be at the desired control level.

5