DF Series

Hydrostatic Head Level Switches

The DF series are diaphragm-operated hydrostatic head pressure level switches. A pressure sensitive diaphragm operates a snap-switch that can be wired directly to electric pilot circuits to control pumps at predetermined levels. Typical application is to start and stop electric driven pump(s) to maintain tank levels. It is also applicable to engine-driven pumps.

  • Also used in:
    • Saltwater disposal systems
    • Cooling towers
    • Crude oil tanks
    • Waterflood systems
    • Diesel day tanks
    • Sumps

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  • Overview
  • Specifications
  • Diagrams
  • Literature

The nitrile sensing diaphragm is impervious to most liquids and is sensitive enough to control levels with 1/4 in. (6 mm) repeatability. See model descriptions for limits of switch trip point adjustability. Materials include aluminum body, glass-filled nylon bottom plate and a special alloy leaf snap switch as standard.

This simple level switch is highly reliable and can be worked into almost any new or existing system without major modification or special tools.

DF755 is suitable for atmospheric tanks in a non-hazardous area. The SPDT snap-switch for the DF755 is preset for a 4 in. (102 mm) differential in liquid level.

Snap Switch Ratings

  • SPDT: 15 A @ 125, 250 VAC
  • Case/Lid: Aluminum
  • Bottom Plate: Glass-filled Nylon
  • Process Connection: 1 NPT
  • Maximum Pressure Rating: 25 psi (172 kPa [1.72 Bar])
  • Conduit Connection (electrical): 1/2 NPT
  • RoHs Compliant

Dimensions DF Series

Dimensions DF Series

For more information about this product, you can download the related literature here:

Sales Bulletin (94124; revision date – 09/2023)

Installation Instructions (00-02-0831; revision date – 01/2020)