Ex-DNS / Ex-VNS pressure switches and vacuum switches with stainless-steel sensors

Pressure switches in the DNS series are suitable for monitoring and controlling pressures in chemical plants, process engineering and wherever the pressure of aggressive liquids and gases needs to be monitored.

Ex-DNS / Ex-VNS pressure switches and vacuum switches with stainless-steel sensors (1.4571) are suitable for monitoring and controlling pressures in chemical plants, process engineering and wherever the pressure of aggressive liquids and gases needs to be monitored. All components of the sensor system are made of high-grade stainless steel (1.4571) and welded using state-of-the-art methods without filler materials. The pressure sensor is plasma-welded without seals. The device is supplied with a robust housing made of seawater-resistant die-cast aluminium GD Al Si 12. The die-cast aluminium housing is chromated and stove-enamelled with resistant plastic coating. Corrosion tests with a 3% saline solution and 30 temperature cycles from +10 to +80 °C showed no surface changes after 20 days.

For Ex-DNS / Ex-VNS, the switching differential is not adjustable.

Features and benefits

• The Ex-DNS and Ex-VNS series are calibrated for falling pressure.
• This means that the adjustable switching pressure on the scale corresponds to the switching point at falling pressure.
• The reset point is higher by the amount of the switching differential.

Certifications

• IBExU12ATEX1040 according to ATEX 2014/34/EU
• IECEx IBE 14.0077
• SIL2 according to IEC 61508-2

Specifications

• Switching differential: 0.002 bar (air pressure)
• Minimum operating ambient temperature: -20 °C
• Maximum operating ambient temperature: 60 °C
• Brand: FEMA | Honeywell
• Switch configuration: SPDT microswitch; capacity 2 A inductive, 3 A resistive
• Scale calibration: falling pressure
• Pressure type: overpressure, relative
• Connection type: internal thread G 1/4″, external thread G 1/2″