I. Product Overview
The ST01 flow switch is a flow monitoring device based on the principle of a reed switch, specifically designed for detecting the on/off state of water flow in liquid pipeline systems. It employs a baffle-type structure, relying on the thrust of the water flow to drive the magnet, causing the reed switch contacts to output a switching signal, thus achieving real-time feedback on the system’s water flow status.
This product model is widely used in scenarios such as water shortage protection for gas water heaters/wall-hung boilers, interlock control of central air conditioning water systems, water shortage protection for water treatment equipment, and water pump dry running protection.
II. Main Technical Parameters
| Project | Parameters |
| Connector specifications | C3B-3P 2×350
Double blue wires (Blue wire 1: Switch signal output terminal; Blue wire 2: Common terminal COM. ) |
| Water pressure resistance | ≤ 1.75 MPa |
| Switching power | 10 W |
| Working flow range | 2 ~ 45 L/min |
| Startup traffic range | 2.0 ~ 3.0 L/min |
| Close traffic range | 1.5 ~ 2.5 L/min |
| Insulation resistance | ≥ 100 MΩ |
| Maximum electrical parameters | DC ≤100 V / AC ≤110 V，电流 ≤0.5 A |
| Switch lifespan | ≥10⁸ times |
| Switch response time | ≤0.2 S |
III. Typical Application Scenarios
| Application areas | Function Description |
| Gas water heater/wall-hung boiler | Automatically cuts off heating or ignition when there is no water flow to prevent dry burning. |
| Central air conditioning water system | Interlock shutdown to protect the compressor in case of water flow interruption. |
| Water treatment equipment | An alarm will sound and the pump will stop when there is a water shortage to prevent dry running. |
| Industrial circulating water system | When cooling water flow is interrupted, an alarm or shutdown will be triggered. |
IV. Installation and Usage Precautions
- Installation direction:It must be installed vertically in accordance with the arrow direction marked on the valve body to ensure that the water flow direction is consistent with the arrow, otherwise the accuracy of operation will be affected.
- Anti-magnetic interference:When assembling the whole machine, ST01 should be kept at least 2 cm away from strong magnetic sources (such as motors, solenoid valves, transformers, etc.) or magnetic objects, otherwise it may cause malfunction or decrease in sensitivity.
- Pipeline cleaning:Before installation, ensure that there are no welding slag, iron filings or other impurities in the pipeline to avoid jamming the baffle or damaging the sealing structure.
- Electrical connection:Do not exceed the voltage/current limits (DC≤100V / AC≤110V, ≤0.5A). It is recommended to use an intermediate relay for signal isolation to extend contact life.
- Pressure resistance test:The system water pressure must not exceed 1.75 MPa, otherwise it may cause the shell to deform or the seal to fail.
