Flow Control Equipment
Flow Switches
A flow switch is a safety device that detects when flow starts or stops in a pipeline via a paddle or magnetic piston and opens or closes an electrical contact.
It is used to prevent pumps running dry, for flow control in boiler and chiller circuits and for alarms. The product range includes 1″–8″ paddle models and plastic-bodied magnetic models.
DN25 – DN300paddle type pipe size
15 A 250 VACpaddle contact rating
IP65protection (plastic housing)
−20 … +90 °Cfluid temperature
Main Applications
- Pump dry-run protection
- Boiler and chiller flow control
- Chilled water circuit alarm
- AHU coils
- Treatment and dosing systems
- Heat pump circuits
Technical Data
| Operating principle | Paddle (bellows micro switch) or magnetic piston |
|---|---|
| Pipe size | DN25–DN300 (paddle; paddle length set to size) |
| Connection | 1″ male thread (paddle), 1/2″ BSP in-line (magnetic) |
| Maximum pressure | 10–16 bar; 25 bar on plastic-bodied magnetic type |
| Fluid temperature | −20 … +90 °C; up to +110 °C on plastic-bodied type |
| Paddle | AISI 304 stainless steel |
| Contact rating | 15 A 250 VAC (paddle), 1 A 250 VAC (magnetic) |
| Contact arrangement | Common / normally open / normally closed |
| Protection class | IP65 (plastic housing paddle), IP54 (magnetic) |
| Setting | On-off threshold by screw (depending on model) |
Material Options
| Part | Bellows paddle (steel case) | Paddle (plastic housing) | Magnetic piston (in-line) |
|---|---|---|---|
| Case | St 37.2 steel, ABS cover | Polypropylene | Brass body |
| Sensing element | AISI 304 paddle set | AISI 304 paddle | Magnetic piston |
| Contact | 15 A 250 VAC | 15 A 250 VAC | 1 A 250 VAC |
| Operating limit | 16 bar / 90 °C | 10 bar / −20…+90 °C | 10 bar / 90 °C |
Which material? On the paddle type, the paddle is trimmed to suit the pipe size; on low-flow lines the magnetic piston type gives more sensitive results. Values come from the flow measurement manufacturer sheet.
Advantages
Pump Protection
- Prevents dry running
High Contact Rating
- 15 A paddle type
Wide Size Range
- DN25–DN300
Contactless Option
- Magnetic piston
Construction and Design Features
- Paddle or magnetic piston
- Micro switch
- Threaded connection body
- Setting screw
Send the pipe size, fluid, temperature and contact needs; we will confirm a suitable flow switch from stock.
How to Choose?
- Determine size and connectionChoose pipe size and thread.
- Check the pressureConfirm line pressure is within the switch limit.
- Fluid and temperatureState water, glycol or other fluid and temperature.
- Type and contactChoose paddle or magnetic type by contact rating.
Complementary Products
Booster Sets & Hydrophores
Circulation Pumps
Sight Flow Indicators
Pressure Measurement and Control Equipment
Pressure Gauges
Level Control Devices
Why ORFA?
Since 1985Over 40 years of experience in supplying industrial piping equipment.
Technical ConsultancyTechnical support on flow switch setting and paddle length.
Delivery from StockPaddle and magnetic flow switches are shipped from stock.
Compatibility CheckCompatibility with Booster Sets & Hydrophores is checked for pump protection.
Get a quote for your project
Our sales team will prepare the best solution for your needs.