Setpoints from 10″ w.c. to 200 psid – Rated 1500 psig, Weatherproof

Explosion-proof, heavy duty, industrial unit has a unique new design which provides sensitivity to differential pressures as low as 10 inches of water (254 mm w.c.), yet handles total pressure of 1500 psi (103 bar). Unlike common differential pressure switches that use a piston-type motion transfer, the Series H3 utilizes a rotary motion transfer shaft that prevents a change in total pressure from causing a setpoint shift. Unit yields deadbands approximately 5% of range, with zero setpoint shift due to variation in working pressures. Friction is minimized and repeatability increased by allowing range spring to act directly on diaphragm plate. Rolling diaphragm design maintains constant effective area to further reduce friction. Diaphragm is allowed to “seat”, allowing application of full rated pressure, up to 1500 psi (103 bar), on either high or low pressure port, without damage. Special over-travel feature prevents overtightening of range adjust screw. Choose optional 316SS chamber for water and water-based fluids or harsher applications.

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NEMA 4X Enclosure, Low Differential Set Points
The Series DX is a differential pressure switch that makes a contact output based on the differential between two pressure sources. Wetted materials of brass and flouroelastomer are suitable for use with most gases and water based solutions. The switch can be used for low differential pressure indication with set point on a decrease of pressure as low as 1 psid (0.07 bar). Differential set point ranges are available from 2.5 to 75 psid (0.17 to 5.17 bar) on increasing differential pressure and 1.0 to 67 psid (0.07 to 4.62 bar) on decreasing differential pressure. Unit features a high static pressure rating of 200 psig (13.8 bar) for higher static pressure applications. Standard is a weatherproof, UL type 4X, enclosure for dust laden, outdoor, or wash-down installation environments.

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Explosion-proof Differential Pressure Switch

Compact, Low Cost, Explosion-proof and Weatherproof

Model 1950 Explosion-proof Differential Pressure Switch combines the best features of the popular Dwyer® Series 1900 Pressure Switch with an integral explosion-proof and weatherproof housing, making it an exceptional value for either application. It is CE, UL and CSA listed, FM approved for use in Class I, Div 1, Groups C and D, Class II Groups E, F, and G and Class III hazardous atmospheres NEMA 7 & 9. Raintight NEMA 3 (IP54). Weatherproof features include a drain plug and O-ring seal in cover. Electrical connections are easily made by removing front cover. For convenience the set point adjustment screw is located on the outside of the housing. Twelve models offer set points from .03 to 20″ w.c. (7.5 to 5 kPa) and from .5 to 60 psi (0.035 to 3.5 bar). The unit is very light and compact – about half the weight and bulk of other explosion-proof or weatherproof switches with separate enclosures.

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ATEX Approved 1823 Differential Pressure Switch

The 1823 in Flame-Proof ATEX Enclosure

Essential for industrial environments, the ATEX approved Series AT21823 combines small size with 2% repeatability. Set point adjustment inside the switch allows for set point settings across 9 ranges from the low of .07 in w.c. to a maximum 85 in w.c. differential pressure. Series AT21823 flame-proof ATEX enclosures are available in aluminum and are ideal for low pressure hazardous area applications. Various housing options such as an overpressure relief valve or external setpoint adjustment knob are available. External setpoint knob allows adjustment without opening the enclosure.

Important notes for installation:
• Cables must be fitted through 1/2″ NPT cable gland or ATEX conduit (not supplied with instrument).
• Make sure after cabling to close tight cover and cable gland, in order to keep IP66 rating (IP65 with option OPV, overpressure relief valve).
• Open cover only after de-energizing instrument.
• Attention: Check local safety rules and warnings on unit and manual for a correct use of the instrument in hazardous area.

Please see SERIES 1800 for non-ATEX approved.

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Our most popular Differential Pressure Switch is now available in an flame-proof ATEX approved package in the AT11910 Series. This pressure switch combines advanced design and precision construction to make these switches able to perform many of the tasks of larger, costlier units. For air and non-combustible compatible gases, the AT11910 Series switches have set points from 0.07 to 20 in w.c. (1.8 to 508 mm). Set point adjustment is easy with range screw located inside the switch enclosure. Series AT11910 ATEX enclosures are available in aluminum enclosures and ideal for low pressure, hazardous area applications.

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The Series ADPS Adjustable Differential Pressure Switch is designed for pressure, vacuum, and differential pressures. The dual scaled adjustment knob in inches water column and Pascals allows changes to the switching pressure to be made without a pressure gage. The ADPS is available with settings from 0.08″ w.c. (20 Pa) up to 16″ w.c. (4000 Pa). The silicone diaphragm and PA 6.6 body make the series ADPS ideal for use with air and other noncombustible gases. The compact size, adjustment knob and low cost make the ADPS the perfect choice for HVAC applications.

Please see SERIES AT1ADPS for ATEX approved.

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The Model 1950G Explosion-Proof Switch combines the best features of the popular Dwyer^® Series 1950 Pressure Switch with the benefit of natural gas compatibility. Units are rain-tight for outdoor installations, and are UL listed for use in Class I, Groups A, B, C, & D; Class II, Groups E, F, & G and Class III atmospheres, Directive 94/9/EC (ATEX) Compliant for CE ATEX II 2G Exd IIB+H2 T6, CSA & FM approved for Class I, Div. 1, Groups B, C, D; Class II, Div. 1, Groups E, F, G and Class III atmospheres IECEx Ex d IIB+H2 T6 (-40°C < Ta < +60°C). The 1950G is very compact, about half the weight and bulk of equivalent conventional explosion-proof switches.

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