Email Us

Thermal Flow Switch (No moving parts)

Thermal flow switch is developed for controlling of water,air,oil and it has no moving parts. It is an ideal choice to replace mechanical flow switch,e.g.paddle flow switch. It can work as water flow indicator, air flow indicator,etc.

More details

Thermal flow switch is also called as thermal differential flow switch or thermal dispersion flow switch and it has no moving parts,so it solves the problem of mechanical flow switches,e.g. paddle flow switch. Though its first investigation is a little higher than paddle flow switch or other mechnical flow switches, but its life time and accuracy and function is powerful than mechanical type.


Thermal flow switches can be used for water, air,oil,etc in closed pipe and have been widely used in many industires. The flow switch has no parts for maintanance, convenient installing, extreme low pressure loss, compact body,LED indication.Thus, the flow switch can work as flow indicator. It can support analog output(4-20mA) or switch signal, which includes NPN,PNP,Relay,etc. It can be used for penumatic or hydraulic sytem, water supply, flow stop monitor of cutting fluids and lubricants, HVAC, protection of pump empty running,etc.


Technical Parameters

1).Setting range: 1-150cm/s(water);3-300cm/s(oil);20-2000cm/s(air)

2).Power supply: DC24V+/-20%

3).Connection current: Max 400mA(NPN or PNP); Max 4A(Relay)

4).No-load current: Max80mA

5).Signal output: NPN,PNP,Relay; ON+OFF(SPDT)

6).Pressure range: 100bar

7). Temperature gradient: 4 deg.C/s

8).Reponse time: 1-12s(typical 2s)

9).Initialization time: 8s;

10).Protection class: IP67;

11).Fluid temperature range:-20-80 deg.C.

12).Environment temperature range:-20-80 deg.C.

13).Storing temperature range:-20-100 deg.C.

14).Wiring way: M12 /2 meters wire optional

15).Mateiral: Stainless

16).LED indication can show working status and flow trends

18).Can be used for pipe size of DN20-DN100mm. Probe length is decived by pipe size.

19).Electrical protection: anti-verse, short circuit,overload protection.



1.Plastic PBT + stainless probe can be made as requirement. Its price is lower than standard version.

2.If used for anti-corrosion application, we can make special items accordingly. Please indicate while order.

3.If require digital display, we can make it.