Flow switch is a kind of measurement instrument which could real-time monitor the liquid and air flow in the pipeline, and output signal at the same time.This product adopts all metal case, no moving parts, the switch quantity can be continuously adjustable, pressure loss is small, compact structure, a plurality of LED real time display of flow state and the state of the switch. Easy installation, suitable for a variety of diameter of product requirements, can be used to monitor the fluid in the pipeline flow, stop idling protection monitoring or prevent pump. Widely used in the hydro-power industry, industrial hydraulics of flow monitoring.
1.All stainless steel shell, no moving parts, no need for any interference
2.Easy installation, suitable for various pipe diameter requirements
3.Switching output, adjustable on-site connection of control points
4.LED real-time display of flow status and switch status
Technical Data |
Product code |
QDB118 |
Measure range
|
3~300cm/s(Liquid) 200~300cm/s(air)
|
Power supply
|
24±20%VDC
|
Current consumption:
|
<90mA
|
Signal output
|
Relay(SPDT)/PNP
|
Transistor characteristics
|
Switch voltage |
24±20%VDC |
Switch current |
≤1.2A |
The relay characteristics
|
Switch voltage
|
≤250VAC/30VDC |
Switch current |
≤3A |
The initialization time
|
typical value 8s(2~15s)
|
Response time
|
typical value 2s(1~15s)
|
Temperature gradient
|
max250ºC/min
|
Protection
|
IP67
|
Medium temperature
|
-20~80ºC
|
Ambient temperature
|
-10~70ºC
|
Storage temperature |
-20~85ºC |
Pressure rating |
10MPa |
Probe materials |
304/316 stainless steel |
Housing material |
304 stainless steel |
M12*1 The definition of connection
Electrical definitions--The wiring diagram
1.To install the product, the probe need to be fully immersed in the fluid, if install to a tube with small diameter, please pay attention to avoid push the probe on the tube wall.
2.When the fluid can not be completely filled pipes, product to be installed at the bottom of the tube.

3.If the pipeline has sediments, please install the product at the side wall of the pipe, horizontal installation, to avoid air and sediment
4.Install the product in a straight or curved intersection distance, pipe length should not less than 4 times the diameter of the pipeline.
After install the products on the pipe, please connect the wire connection according to the electrical definition. Switch on the power, then adjust product after 2 minutes.
As shown in the picture above, screw off the anti-dust screw, then we could see the adjustment point of potentiometer. Standing at the cable entry side, rotate the adjustment point in clockwise, the indicator would lights from left to tight in order, light off conversely.
For different applications, follow the steps below to adjust, If the adjustment effect is not ideal, it can be repeated for several times.
NOTE:When the velocity of fluid flow changes from 15 to 30 seconds, then adjust the potentiometer.
1.Medium flow / reduce the flow rate
a.Set the minimum flow rate or the standard flow rate lower than the set monitoring flow rate
b.Adjust the potentiometer, make the right indicator LED lights
c.Restore the monitoring flow rate, adjust the potentiometer, make the yellow indicator lights and at least one green indicator lights
2.Media presence / absence
Adjust the potentiometer, when the pipeline medium does not flow, make the red indicator lights, when the medium flows, make yellow and at least one green indicator lights.
3.Medium flow / still
Adjust the potentiometer, when there is no medium in the pipeline, make the red indicator light on, when there is a medium in the pipeline or there is a certain flow rate, make the yellow and at least one green indicator light on.
1.You should read this manual carefully before use, correct wiring.
2.Before turning on power supply voltage on the product, confirm the power supply range, high pressure could damage the product;
3.Pay attention to direction & method of installation.
From the date of delivery within a year, the company has quality defects caused by material and technology problem free replacement or repair of product; product failure caused by the use of the process of non quality reasons, the company responsible for the repair, only charge the cost of the material.
Please use the machine comply with the User Guide.













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1. How long will you reply to me?
Normally in 1 hours, no more than 12 hours.
2. How can I get the quotation?
Please provide specification and application including sensing element, pressure range, thread connection, pressure type, medium, electronic connection, shell material etc. More details, more accurate quotation and earlier response.
3. Can I get sample?
Contact with our staff online directly and they would check stock for you.
4. Can I visit your factory?
You are warmly welcomed, our factory is located at Baoji city, Shaanxi province, China.
5. Can we use our logo on the products?
Yes, we provide OEM/ODM service.
6. How long is your warranty period?
Warranty period from the date of acceptance of 12 months.
7. What is your terms of payment?
We could accept T/T, L/C, Western union, PayPal, credit Assurance.