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Diaphragm Switch
Performance under pressure
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 in the vessel. Commonly used in grain, feed, seed or other free-flowing granular material, BinMaster diaphragm switches are offered for either internal or external mounting. They are wired to a light, horn, alarm, or BinMaster point level alarm panel to indicate an alert status.
Affordable and Durable
BinMaster diaphragms are made in the USA at our plant and are the most economical point level detectors. True to our original 1960s design, they operate simply and withstand years of use. Their die-cast aluminum housing withstands harsh, seasonal weather extremes like we have in Nebraska.
Simple to wire. Mechanical operation. Very few moving parts. Pick from neoprene or silicone diaphragm materials and Internal or external mounting options. An occasional replacement diaphragm or simple switch are all you will ever need for decades of use.
BM-45
Standard Diaphragm Switch
The BM-45 is a simple, low-cost point level control with proven, lasting reliability. It is intended for use in bins containing non-hazardous, free-flowing dry materials. The BM-45 is offered in six different models including standard or heavy-duty neoprene, or heavy-duty silicone diaphragm material and either internal or external mounting options.
BM-65
Diaphragm Switch for Hazardous Locations
The BM-65 diaphragm switch is UL Class II, Groups E, F & G explosion-proof certified and can be used in environments where there is a risk of combustible dust. The BM65 is commonly used in agricultural products such as grain, cornstarch, flour, sugar, or rice. Metals such as aluminum or zinc; chemical dusts like coal or sulfur; plus some pharmaceuticals, pesticides, rubber, or wood products are materials where a BM65 may be used.
| Model | Mounting | Diaphragm Material | Temperature | Bulk Density | Location |
|---|---|---|---|---|---|
| BM45-R | Internal | Neoprene, Black, .016" Thick | -30° to 220°F | 10 to 40lb/cu. ft. | Non-Hazardous |
| BM45-RH | Internal | Neoprene, Black, .031" Thick | -30° to 220°F | 15 to 60lb/cu. ft. | Non-Hazardous |
| BM45-RHT | Internal | Silicone, Grey, .031" Thick | -40° to 350°F | 15 to 40lb/cu. ft. | Non-Hazardous |
| BM45-F | External | Neoprene, Black, .016" Thick | -30° to 220°F | 10 to 40lb/cu. ft. | Non-Hazardous |
| BM45-FH | External | Neoprene, Black, .031" Thick | -30° to 220°F | 15 to 60lb/cu. ft. | Non-Hazardous |
| BM45-FHT | External | Silicone, Grey, .031" Thick | -40° to 350°F | 15 to 40lb/cu. ft. | Non-Hazardous |
| BM65-R | Internal | Neoprene, Black, .016" Thick | -30° to 220°F | 15 to 60lb/cu. ft. | Hazardous |
| BM65-RH | Internal | Neoprene with Nylon Mesh, Black, .020" Thick | -30° to 275°F | 15 to 90lb/cu. ft. | Hazardous |
| BM65-RHT | Internal | Silicone, Grey, .031" Thick | -40° to 350°F | 15 to 60lb/cu. ft. | Hazardous |
| BM65-F | External | Neoprene, Black, .016" Thick | -30° to 220°F | 15 to 60lb/cu. ft. | Hazardous |
| BM65-FH | External | Neoprene with Nylon Mesh, Black, .020" Thick | -30° to 275°F | 15 to 90lb/cu. ft. | Hazardous |
| BM65-FHT | External | Silicone, Grey, .031" Thick | -40° to 350°F | 15 to 60lb/cu. ft. | Hazardous |
Diaphragm materials
Neoprene — is a type of synthetic rubber that is abrasion-resistant, chemical-resistant, waterproof, stretchable, and buoyant.
Silicone Rubber — has the best long-term resistance to environmental extremes. Its chemical, electrical, and mechanical properties remain virtually unchanged at temperatures from -160° to 500° F.
Neoprene with Nylon Mesh — has outstanding resistance to most chemicals, heat, and oils, has low moisture absorption, and good dielectric qualities. It is flame resistant, weather resilience, and extremely high abrasion resistance.
BM45 and BM65 models using neoprene with nylon mesh and silicone diaphragms have a thicker .031” diaphragm and a snap-action switch that is less sensitive than the standard switch. These units are intended for use with heavier materials and low-level installation within the bin. The silicone diaphragm will remain more resilient and sensitive in extreme temperature conditions
Plugged Chute Detection
The BM65-FHPC and BM-65-RHPC are designed to alert when a chute becomes clogged with material. These plugged chute detectors feature a heavy spring and rugged diaphragm material. They have UL Class II, Groups E, F, & G explosion-proof certification and can be used in hazardous environments where there is a risk of combustible dust.
When a chute becomes plugged, an audible or visual alert is activated when the device is wired to a horn, siren, light, or alarm panel. These plugged chute detectors are intended for process temperatures ranging from -30°F to 270°F and material bulk densities from 15 to 90 lb./cu. ft. They are ideal for use in chutes transporting flowing grain, seed, feed, or other granular or pelleted materials.
Mounting the Diaphragm Switch
The diaphragm switch is offered in models for either internal or external mounting. External mounting requires cutting a hole in the bin wall. Installing or replacing an externally mounted diaphragm switch is performed easily from outside the bin. Internal mounting does not require a hole to be cut, but installation must be done inside of the bin, preferably when it is empty.
Pressure Activated Switch
When material reaches the level of the diaphragm switch as the bin is filled, it presses against a sensitive micro-switch activating an alarm status. The switch is often wired to start or stop a process or alert to high, medium, or low levels in bins.
Best in Dry Solids
A diaphragm switch is for point level detection of free-flowing dry materials. Use them in bins or silos, and some plugged chute applications. Activated by pressure, they must be used in materials with a bulk density more than 15 lb./cu. ft.
Detects Materials from A to Z
Introductory video about diaphragm switches.
See where diaphragm switches are made.
Get to know all the BinMaster sensors.
Affordable BM-25 pressure switch for solids.
Wiring a BM-25 pressure switch to a light.
