DWU, DWS and DWP Paddle/Bellows Flow Meter and Switches From Kobold Instruments

Paddle/Bellows Flow Meter and Switches KOBOLD Model DWU, DWS and DWP Paddle/Bellows Flow Meter and Switches are based on the paddle, or static plate, principle. This type of arrangement is ideal for use in applications where dirt and solid grain contaminants are of concern. The paddle-bellows arrangement offers large internal clearances and mechanical insensitivity to a wide range of particulate matter.


The simplicity of the DW Series Paddle/Bellows Flow Meter and Switches design is its major asset. The devices operate as follows:

  • The flow causes the paddle, or static plate to be deflected in the direction of flow against the force of a spring. A bellows, made of bronze (or preferably stainless steel), hermetically isolates the medium from the measuring/indicating section. The motion of the paddle is transmitted directly to a mechanical indicator and switch, or to a signal conditioner in the case of analog output versions.

  • The DW Series of Paddle/Bellows Flow Meter and Switches comes in a variety of mounting styles. Units are available mounted in a pipe TEE for in-line installation into pipes to 2-1/2" with either threaded or flanged ends. For larger pipe applications, the DW is available in a weld-on design usable on pipes with diameters up to 24 inches.

Analog Output Option

For installations requiring remote indication of flow, we offer the DW Series of Paddle/Bellows Flow Meter and Switches with optional analog output (option »-AN«). The meter continues to function in the standard way, except that rather than a mechanical dial movement, an inductive motion transducer is input to a signal conditioning circuit which provides a 4-20 mA flowrate signal and LCD display. The analog output option allows for remote transmission of system flowrate. A three digit LCD display with 0.4" tall characters is standard with all analog output versions making quick flow rate readings a snap.

Switching capability is not part of the standard configuration with option -AN analog output meters. If switching capability is desired in addition to the analog output, 2 external relays can be provided as part of the transmitter electronics.

Special Features:

  • Accuracy: ± 3% Full Scale

  • Paddle Bellows Design Excellent for Highly Contaminated Media

  • Orientation Independent

  • Brass or Stainless Steel

  • High Current Switching Capability

  • Insensitive to Magnetic Fields

Product Specifications:

0 to 6 GPM: ± 5% of full scale
6 to 60 GPM: ± 4% of full scale
Over 60 GPM: ± 3% of full scale
Flow Media: Liquids
Flow Range: 0.65 to 18 ft/sec
Max/Min Ratio

Additional Product Info
Download Specifications
Product Manual