Mechanical Piston Flow Switch for Liquid & Gas NK-800

Product Overview

The Mechanical Piston Flow Switch for Liquid & Gas NK-800 is designed for flow monitoring and control of liquids and gases in small-diameter pipelines. It is intended for low-flow applications and is not suitable for high-temperature media.

This inline mechanical flow switch combines a durable piston mechanism with magnetic actuation to provide reliable flow detection for industrial systems. It is suitable for use in industrial automation, machinery, air compressor systems, refrigeration, and HVAC applications.

The flow switch is available with plastic, aluminum, or stainless steel housings, allowing users to select the most suitable material for different operating environments.

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Working Principle

The flow channel inside the flow switch housing contains a piston equipped with a permanent magnet.

As fluid flows through the pipeline, the pressure differential generated by the flowing medium pushes the piston forward. The magnetic piston actuates the sealed magnetic switching mechanism inside the device, causing the switch output to change state.

The diameter of the piston determines the starting flow rate.

When the flow rate decreases, the stainless steel spring returns the piston to its original position. Once the reed switch is actuated, it can provide a remote alarm signal or status indication.

The flow switch is suitable for both liquid and gas media.

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Product Features

• Inline mechanical flow switch
• Suitable for both liquid and gas applications
• Designed for small-diameter pipelines
• Low pressure loss
• Excellent repeatability
• Strong resistance to contamination
• Complete isolation between mechanical and electronic components
• Economical solution for low-flow monitoring
• Piston stroke increased to three times that of the original NK-HS200, providing improved switching accuracy
• Integrated flow switch setting scale eliminates the need for on-site adjustment
• LED indication of switch status (DC power supply models)
• Dual switching outputs available
• Durable housing options:
  • Plastic
  • Aluminum
  • Stainless Steel

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Typical Applications

The Mechanical Piston Flow Switch is suitable for a variety of industrial applications, including:

• Industrial automation
• Mechanical equipment
• Air compressor systems
• Refrigeration systems
• HVAC systems
• Cooling water monitoring
• Lubrication systems
• General liquid and gas flow monitoring

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Technical Specifications

Setting Range

Please refer to the detailed specification table for the available flow setting ranges.

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Measurement Accuracy

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Hysteresis

The hysteresis depends on the selected switching point, with a minimum value of 0.5 L/min.

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Switch Setting Calibration

The switch setting scale is calibrated under the following standard conditions:

• Medium: Water
• Medium Temperature: 20°C
• Installation Position: Horizontal

Please note that changes in the process medium and operating temperature may slightly affect the switching point.

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Installation

The flow switch is designed for inline installation.

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Electrical Connection

Standard connection:

• M12 5-pin connector

Optional connection:

• Hirschmann connector

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LED Status Indication

• DC-powered models include an LED indicator for switch status.
• AC-powered models do not include LED indication.

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Output

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Pressure Rating

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Pressure Loss

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Temperature

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Protection Rating

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Wiring diagram

Size chart

Product Advantages

The Mechanical Piston Flow Switch combines a magnetic piston operating principle, low pressure loss, and high repeatability to provide reliable flow monitoring in liquid and gas systems.

With its complete mechanical and electrical isolation, durable housing options, adjustable switching scale, and optional dual switch outputs, it is well suited for industrial applications requiring dependable and economical flow protection.

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Frequently Asked Questions (FAQ)

What media can the Mechanical Piston Flow Switch monitor?

The flow switch is suitable for both liquids and gases.

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Is this flow switch suitable for high-temperature media?

No. This model is primarily designed for small-diameter pipelines and is not recommended for high-temperature media.

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How does the flow switch operate?

The flow switch uses a magnetically actuated piston. Flow creates a pressure differential that moves the piston, activating the internal reed switch. When flow decreases, a stainless steel spring returns the piston to its original position.

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What electrical connections are available?

The standard electrical connection is an M12 5-pin connector, with an optional Hirschmann connector available.

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Does the flow switch include a status indicator?

Yes. DC-powered models feature an LED indicator that displays the switching status, while AC-powered models do not include LED indication.

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Why Choose the Mechanical Piston Flow Switch?

The Mechanical Piston Flow Switch provides a reliable and economical solution for monitoring liquid and gas flow in industrial systems. Its magnetic piston design, low pressure loss, excellent repeatability, LED status indication, and multiple housing options make it an ideal choice for industrial automation, air compressor systems, refrigeration equipment, and HVAC applications.