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Ex PC-Workstations, Ex-PCs

Ex Automation technology

Ex-p Pressurized enclosures


F830 F840 F850-SYST F850S F850U F860S F870S OEM SR852 SR853
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Ex pz- control unit FS840 - Description

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Concept

The use of simplified pressurized enclosures allows the operation of 'non explosion protected' devices in hazardous areas inside zone 2.

The protection type 'pressurization' is based on the principle of maintaining a constant pressure using air or a protective gas to prevent an explosive mixture forming near the apparatus inside the pressurized enclosure.

Generally before start-up, the pressurized enclosure must be purged with air or protective gas to remove any explosive mixture that may be inside the enclosure. This automatic procedure is called purging process.

Simple assembly

An simplified pressurized enclosure system consists of two components and the enclosure.

  1. control unit FS840 for process control and monitoring
  2. Sinter metal throttle SD840 to control air input fed by pressured air network

See manual F840 for requirements of pressurized enclosure and integrated ignition capable apparatus.

Selectable Automatic pre- purging

If the operator is not sure, that the atmosphere inside of the enclosure and the appropriate pipe infrastructure is below 25% of the lower explosive limit (LEL) (EN 60079-14 chapter 13.4), the enclosure must be purged to achieve a safe atmosphere inside of the enclosure.

The F840 system can purge the enclosure automatically using the solenoid valve SVD.L. In this case the SVD.L replaces the sinter metal throttle.

  last modified: 06.11.2009