Kewill Global


Mechanical type flow switch.Built-in spring supporting baffle sheet, when the flow rate reaches a prefabricated value, the mechanical structure of microswitch trigger trigger switch.



On line installation,Minimal pressure loss, good repeatability, dirt-resistance, through the knob to achieve accurate switch setting.hermetic separation of mechanical.


The gas-liquid dual-purpose type, industrial automation / mechanical equipment / air compressor industrial /refrigeration and air conditioning .Applied to diameter of the pipeline ≤50mm.



DN Interface thread Type Withstand voltage Adjustable Range Hysteresis
D bar L/min(Pure water) L/min(Pure water)
15 RC 1/2″ Taper pipe thread FB31-015FM1 16 or 40 3…11 1.5
RC 1/2″ Taper pipe thread FB31-015FM2 16 or 40 5…17 2.5
20 RC 3/4″ Taper pipe thread FB31-020FM1 16 or 40 4.2…18 2
RC 3/4″ Taper pipe thread FB31-020FM2 16 or 40 8.3…37 3
25 RC 1″  Taper pipe thread FB31-025FM1 16 or 40 5.2…23 2
RC 1″ Taper pipe thread FB31-025FM2 16 or 40 11…48 4
32 RC 1 1/4″ Taper pipe thread FB31-032FM1 16 or 40 8.1…39 3
RC 1 1/4″ Taper pipe thread FB31-032FM2 16 or 40 19…90 6
40 RC 1 1/2″ Taper pipe thread FB31-040FM1 16 or 40 15…69 5
RC 1 1/2″ Taper pipe thread FB31-040FM2 16 or 40 25…111 7
50 RC2″ Taper pipe thread FB31-050FM1 16 or 40 35…92 6
RC 2″ Taper pipe thread FB31-050FM2 16 or 40 46…125 7

Note: The above parameters is going to switch vertically installed in the horizontal pipeline,at 20℃ water as medium .

The above example models material is 316L stainless steel (we have bronze material can be option)


●Setting range: See bellow table
●Repeatability: ±2.5% of full scale
●Connection type: Terminal connection
●Output: Mechanical switch  NO+NC (250VAC,3A)
●Withstand voltage: 16 bar(40bar optional)
●Avg pressure loss: 0.08bar(Max. flow)
●Ambient temp.: -25…80℃
●Medium temp: 0…90℃ (-30…350℃)
●Protection class: IP54&IP57
●Material: Body:   316L stainless steel
Process connection: brass alloy/316L stainless steel
Connecting rod:brass alloy/316L stainless steel
Paddle:316L Stainless steel
Seals:  NBR
Protection shell: Fire class carbonate polymer&316L stainless steel



Note: installation position may

influence switch value.







FB31- FB31 Series Paddle flow switch
DN applicable 015   RC 1/2″ Taper pipe thread (DN15)
020 RC 3/4″ Taper pipe thread(DN20)
025 RC 1″ Taper pipe thread(DN25)
032 RC 1 1/4″ Taper pipe thread(DN32)
040 RC 1 1/2″ Taper pipe thread (DN40)
050 RC2″ Taper pipe thread(DN50)
A Customer specified diameter size
Connection type F Internal thread
M External thread
Material M Brass alloy structure UNI EN 12165 CW617N
K1 304 Stainless steel  1.4301  liquid body
K2 316L Stainless steel  1.4435  liquid body
Detail data 1 See technical data with diameter appropriate to the range of adjustment range
2 See technical data with diameter appropriate to the range of adjustment range
Protection cover material P Fire class carbonate polymer protection shell
K 316L stainless steel protection shell


VARRIO /F Special connection type:flange connection
/HP High voltage 40bar
/HT Withstand high temerature 350 degree(IP67)


FB31 Series

Flow switch , brass (stainless steel).The baffle sheet, corrugated pipe, support and other internal components for stainless steel.Suitable medium: water, oil, air, ethylene glycol solution. Max.working pressure of 40 bar. Medium temp.-30…350 C. Power supply: 250V, 3A. Protection class IP54. Suitable diameter DN15~DN50.