WIKA Diaphragm Pressure Switch, Flameproof Enclosure Ex d (MA)

For the process industry


  • Pressure monitoring and control of processes
  • Safety-critical applications in general process instrumentation, especially in the chemical and petrochemical industries, oil and gas industries, power generation incl. nuclear power plants, water/wastewater industries, mining
  • For gaseous and liquid, aggressive and highly viscous or contaminated media, also in aggressive environments

Special Features

  • Robust switch enclosure from aluminium alloy, IP66, NEMA 4X
  • Setting ranges from 16 mbar to 600 bar, also all other equivalent vacuum or combined pressure and vacuum ranges
  • 1 or 2 independent switch points, high switching power up to AC 250 V, 20 A
  • Switch point repeatability < 1 %

Sales Contact (Wika.sales@asyatrafo.com)




These high-quality mechanical pressure switches have been developed especially for safety-critical applications. The great advantage of mechanical pressure switches is that no supply voltage is required for the switching process.

In production, the switches are traced by quality assurance software at every step and subsequently are 100 % tested. The robust switch enclosure from aluminium alloy can withstand the rough and corrosive operating conditions of the process industry with working ranges of up to 600 bar.
The pressure switch is fitted with 1 or 2 microswitches, which make it possible to switch an electrical load of up to AC 250 V, 20 A directly.

For lower switching power ratings, such as for PLC applications, argon gas-filled microswitches with gold-plated contacts are available.

Depending on the application, the appropriate variant for the contact version and the electrical connection can be selected; e.g. adjustable dead band instead of fixed dead band is often a feature necessary for control processes.

By using a diaphragm measuring system, the model MA pressure switch is extremely robust and guarantees optimal operating characteristics. Flanged process connections are excellently suited for measuring highly viscous, contaminated or crystallising media.

For applications with special requirements on the wetted parts, versions with materials from PTFE, Monel or Hastelloy are available.

For safety applications, the pressure switch is optionally available in a SIL 2-qualified or a SIL 3-qualified version.