Flow controllers - EX devices
EX sensors
Sensors for gas and dust explosive environments are design approved to ATEX 100a and operated with an approved switching device of series SZA... or SEA... Subject to approval the use of flow monitors is possible in areas for devices of category 1 and category 2.
Stainless steel 1.4571 (AISI 316 Ti) is used as a standard material for all sensors. All other stainless steels such as Hastelloy, Monel and bronzes can be provided on request. Corrosion resistance of the materials to be used must be specifically checked for the intended application.
EX area certification
The sensors belonging to Series 400, as well as amplifiers SEA… and SZA…, have a EG-Type Examination. The corresponding technical limit data and the special instructions concerning incorporation and connection expressed in the certificates of conformity must be complied with.
Use in category 1 and 2 (zone 0 and 1)
In zone 0 and 1 only sensors having an EC design approval per ATEX 100a must be used. If the sensor is installed outdoors, a corresponding lightning protection must also be installed. This accessory is inserted in the sensor line, between the sensor and the switching amplifier. It limits lightning induced voltages in the sensor line and diverts them to earth.
EX devices
For Ex flow sensors switching devices SEA... and SZA are available. They have their own intrinsically safe circuit to which the sensors are connected. This circuit is electrically isolated from the mains circuit and the relays or analog output. Notes on installation:
1. All Ex-Amplifiers must be installed outside the hazardous area.
2. The installation of the amplifier must al least meet protection to IP 20 EN 60529.
3. When installing the amplifier there must be a safe distance between intrinsically-safe and unsafe connections. The minimum distance is 50 mm. Alternatively each connection can be equipped with a shrink-sleeve or crimp connection.
ATEX 100 a
Since 1st July 2003 only devices with ATEX approval may be used in explosive environments throughout Europe. All EGE sensors have the relevant approval.
The operator of a plant is responsible for dividing the hazardous areas into zones. The zones are zone 0, 1 or 2 for gas and zone 20, 21 or 22 for dust. Depending on the requirements of the operator EGE supplies approved devices with approval certificates for the respective zones.
In dust explosive areas the maximum surface temperature of the sensor will always be stated and must be observed by the operator. For gas explosive sensors the approved temperature categories will be stated.
With the exception of mining, sensors can be supplied for all industries. Special dimensions or different materials are also possible.
