Basic Diaphragm Switch

Model: BM-25

BM-25 Diaphragm Switch: Point level detector for bins and chutes

The BM-25 diaphragm switch is a pressure switch for high or low-level alerts in bins containing non-hazardous, free-flowing dry materials.

Need an inexpensive level switch? Want to know when your bins are full or empty?

Reduce overfills and stop wasting valuable grains and fertilizer. Know when chutes or conveyors are clogged before making a mess.

How it works:

A diaphragm (or pressure) switch works by activating a sensitive micro-switch when material reaches the level of the switch in the bin. It sends an alert that can be used to start or stop a process or alert to a high, medium, or low-level.

What to use the BM-25 for:

  • Point level detection in bins and silos
  • Eliminate overflow or maintain a certain level of material
  • Detect plugging of chutes or conveyors
  • Monitoring levels of dry, free flowing materials
  • Material density from 20 lb./cu. ft
  • Installation in ordinary locations
  • Levels of grain, feed, or fertilizer

The BM-25 is great for farmers, ag cooperatives, or any business storing dry bulk solids!


Use this pressure switch in many materials:

  • Corn, soybean, wheat, barley, or milo
  • Dry fertilizer and granular ag chemicals
  • Plastic and rubber beads or resin pellets, regrind
  • Wood pellets, chips, or sawdust
  • Nut crops such as peanuts, sunflower, or sesame seeds
  • Foodstuffs such as rice, wheat, oats, or sugar beets
  • Powdered alumina, bentonite, or potash
  • Landscaping materials

Features of this reliable point level switch:

  • Economical point level detection
  • Rugged construction and simple design
  • Pressure sensing operation
  • Nylon housing
  • Silicone diaphragm material
  • Internal or external mounting

Specifications you need to know about the BM-25:

Switch Ratings: 250 VAC, 15A

Output: Switch contact closure

Operating Temperature: -40°F to + 185°F (-40°C to +85°C)

Enclosure Material: Nylon

Diaphragm Material: Silicone

Wire Entry: ½” NPT

Mounting: Internal or external

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