Emerson Fisher L2, Fisher L2sj Data Sheet

L2 Controller

D103034X012

Fisherr L2 Liquid Level Controller

The rugged Fisher L2 liquid level controller uses a
displacer type sensor to detect liquid level or the
interface of two liquids of different specific gravities.
This controller is ideal for controlling level on gas
separators and scrubbers. The reliability of the L2
design makes it well suited for liquid level applications
in natural gas production, compression, and
processing. The device delivers a pneumatic output
signal to a control/dump valve. The sensor uses a
threaded 2 NPT or an NPS 2 CL150 through 1500
slip-on flange connection to the vessel.

Features

n More Reliable Control—Two-stage proportional

relay with integral action provides more dependable
liquid level control.

Product Bulletin

34.2:L2

September 2013

n Snap-Acting or Throttling Control—One standard

controller available as either throttling or
snap-acting.

n Vibration Resistant Sensor Dynamics— O-ring

friction and process pressure sensitivity are
minimal. Performance stays constant with process
pressure changes and controller remains vibration
resistant.

n NACE Service Ready—Standard construction uses

materials that comply with the requirements of
NACE MR0175-2002.

n Field-Configurable Vertical or Horizontal

Displacer—Displacer may be adjusted in the field for

vertical or horizontal operation without additional
parts.

n Field-Reversible Output—The controller can be

adjusted in the field for direct or reverse action
without additional parts. The controller also has
adjustable gain sensitivity.

W8418-1

n CL1500 Pressure Rating—Sensor assembly is

designed and specified for ASME B16.34 CL1500
service when using a Polyvinylchloride (PVC)
displacer. For PED (97/23/EC) maximum pressure is
limited to 200 bar (2900 psig).

n Vent-Away Case—The ability to pipe away exhaust

permits using natural gas as the operating medium.

n Easy Maintenance—Both the controller and the

sensor can be easily disassembled to inspect the
process seals and for maintenance.

www.Fisher.com

Product Bulletin

34.2:L2
September 2013

Specifications

L2 Controller

D103034X012

Available Configurations

Controllers: Snap-acting or throttling
Sensor: Displacer-type liquid level sensor for

mounting to side of tank. Displacer travel is
transmitted to controller by pivotal movement of
displacer rod

Input Signal

Type: Liquid level or liquid-to-liquid interface

Level Change Required for Full Change in Output
Signal in a 1.0 Specific Gravity Liquid, with 1.4 bar (20
psig) Supply Pressure, Direct Action, and Standard
1-7/8 X 12-Inch (48 x 305 mm) Vertical Displacer with
Standard Lever Arm Length:

Control Mode

Throttling 102 (4) 305 (12)

On-off 127 (5) 305 (12)

Snap-acting 13 (0.5) 20 (0.8)

Minimum Specific Gravity

Minimum Span Level

Change, mm (Inches)

(2)

Maximum Span Level

(1)

Change, mm (Inches)

Throttling Controller: Minimum specific gravity, or
specific gravity differential for interface applications,

(3)

is 0.1

.

Snap-Acting Controller: Minimum specific gravity, or
specific gravity differential for interface applications,
is 0.1

Output Signal

Pneumatic

J on-off or J proportional pressure

signal

Ranges:

Throttling:

J 0.2 to 1.0 bar (3 to 15 psig) or J 0.4 to

2.0 bar (6 to 30 psig)
On-Off: 0 (off) or full supply pressure (on)
Action: Field-reversible between direct (increasing
level increases output signal) and reverse (increasing
level decreases output signal)

Supply Pressure Requirements

Throttling Controller:

Throttling: 1.4 bar (20 psig) for 0.2 to 1.0 bar (3 to 15
psig) output signal and 2.4 bar (35 psig) for 0.4 to 2.0
bar (6 to 30 psig) output signal
On-Off: Any desired pressure between 1.4 and 3.4 bar
(20 and 50 psig)

(1)

-continued-

Snap-Acting Controller: Any desired pressure
between 1.4 and 5.2 bar (20 and 50 psig) direct, and

1.4 and 2.4 bar (20 and 35 psig) reverse
Do not use supply pressure below 1.4 bar (20 psig)

Supply Pressure Medium

Air or natural gas

Steady-State Air Consumption

(4)

(5)

Throttling Controller: ≤0.03 normal m3/hr (1.0 scfh)
at 1.4 bar (20 psig) supply pressure
Snap-Acting Controller: ≤0.03 normal m

3

/hr

(1.0 scfh) at 1.4 bar (20 psig) supply pressure or
≤0.04 normal m

3

/hr (1.5 scfh) at 2.4 bar (35 psig)
supply pressure in tripped condition; air consumption
increases during trip

Sensor to Vessel Connection

J 2 NPT threaded or J NPS 2 CL150 through 1500

slip-on flange connection

(6)

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

Standard Displacer Size

48 x 305 mm, 541 cm

Maximum Displacer Insertion Length

3

(1-7/8 x 12 inches, 33 in3)

(7)

Standard lever arm length plus one 6-inch extension,
horizontal or vertical

Displacer Material and Maximum Sensor Working
Pressure

(8)

PVC Displacer: Consistent with CL1500 pressure
temperature ratings per ASME B16.34 up to
maximum pressure of 258.5 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

2