Platon Liquid Low Flow Alarm
DS1431
Features
Low cost flow alarm
Simple rugged construcꢀon
Brass, BSP connecꢀons
Selectable alarm trip level (factory set)
No glands or seals
Stainless steel and other special OEM versions available
PLATON FLOW ALARM TYPE LF
FLOW RANGES
For liquid low flow or flow failure alarm on cooling systems, water
heaters or lubricaꢀon systems, the Platon LF flow switch is a rug-
ged sensor with simple electrical reed switch output. Installed in a
verꢀcal line with flow upwards, normal flows liꢁ the float in the
sensor. A magnet encapsulated in the float then actuates a reed
switch, giving contact closure. Should the flow drop to below the
preset alarm level, the float falls to the rest posiꢀon and the con-
tacts open to give an alarm output.
The flow trip level set on water for the different models is as
follows:
Connecꢀon Model
Number
Low Flow
Trip Level
1/2” BSP
1/2” BSP
1/2” BSP
1/2” BSP
1/2” BSP
LFB11L
LFB12L
LFB13L
LFB14L
LFB15L
0.5 L/min
1.0 L/min
2.5 L/min
3.0 L/min
3.5 L/min
The Model LF is available in 1/2” and 3/4” line sizes, with BSP
female threaded connecꢀons. Alarm rates are factory set be-
tween 0.5 L/min and 10 L/min, to suit most applicaꢀons. The
standard unit is in brass, and has a one piece body suitable for
high pressures, with no glands or seals to leak. The externally
mounted reed switch has flying leads for local connecꢀon to a
terminal block.
1/2” BSP
1/2” BSP
1/2” BSP
LFS11L
LFS12L
LFS13L
0.5 L/min
1.0 L/min
2.5 L/min
Typical applicaꢀons are for water supply flow failure into heaters
or boilers, where the flame or power supply is cut to prevent
overheaꢀng accidents, for lubricant or cuꢂng fluid flow failure in
machine tools or gearboxes.
For flow failure alarm in cooling circuits, the LF flowswitch is used
on X-ray equipment, electron microscopes,
3/4”BSP
3/4”BSP
3/4”BSP
3/4”BSP
LFB22L
LFB23L
LFB24L
LFB25L
1.0 L/min
2.5 L/min
5.0 L/min
10.0 L/min
transformers, radio transmiꢃers and high frequency
generators.
Typical hysteresis between on/off
Typical accuracy of trip point
±5%
±10%
General Note
TT Electronics | Roxspur Measurement & Control Ltd
2 Downgate Drive, Sheffield, S4 8BT, England |Ph: +44(0)114 244 2521
www.roxspur.com | sales@roxspur.com
TT Electronics reserves the right to make changes in product specificaꢀon without
noꢀce or liability. All informaꢀon is subject to TT Electronics’ own data and is
considered accurate at ꢀme of going to print.
Issue B 7/2017 Page 1
© TT Electronics plc