The KOBOLD DSV-3 is a proven variable area (float-type) reed flow switch for liquid media, based on a patented design that replaces the conventional tapered measuring tube with a cylindrical tube featuring conical slots around its periphery. This innovation eliminates the typical problems of float instability within a tapered glass tube and significantly reduces sensitivity to dirt, ensuring reliable operation even with less-than-perfect fluids.

Working Principle

The device consists of a cylindrical flow tube, a float containing a permanent magnet, and an externally mounted bistable reed switch. As the liquid flows from bottom to top, the float rises. Once its magnetic field reaches the reed switch's contact tips, the contact closes. As flow increases, the float continues to rise until it reaches an internal stop, ensuring the reed contact remains securely closed—providing bistable switching behavior. The float's top edge serves as a visual indicator on the measuring glass tube, allowing the operator to read the approximate flow rate in liters per minute.

Key Features

• Hermetically Sealed Electrical System: The reed switch is completely isolated from the flowing medium, preventing leakage and ensuring safe operation even with aggressive liquids.
• Dirt-Insensitive Design: The cylindrical tube with conical slots minimizes flow obstruction and reduces susceptibility to particulate contamination.
• Adjustable Switch Point: The external reed switch housing is height-adjustable, allowing the user to fine-tune the activation set point to match specific application requirements.
• Built-in Visual Indication: The transparent glass tube allows for direct visual flow monitoring via the float position.
• Robust Construction: Available with brass or stainless steel wetted parts for compatibility with a wide range of industrial liquids.

Applications

The DSV-3 is ideal for monitoring liquid flows in welding equipment, cooling circuits, lubrication systems, and general industrial processes where reliable flow/no-flow detection is required.