December 10, 2015 - E2S Warning Signals introduced a SIL 2 version of its BEx range of explosion proof alarm horn sounders and Xenon strobe beacons. The IECEx and ATEX certified BEx horns and strobes are suitable for designers and integrators of SIL 2 systems; they are designed and tested to ensure a 99.9% reliability rate, bringing plant safety to new levels.
To meet the requirements of SIL 2, a combination of software and hardware in the units accurately monitors and interprets the sound output of the horn or the light output from the Xenon strobe to check it is functioning correctly. The fault monitoring reports back to the control panel utilizing either separate fault contacts or by the introduction to the monitoring circuit of a series resistor. Using the series resistor facility eliminates the need for any additional cables and can be used in a standard two-wire arrangement. The key benefits are:
• The correct functioning of the signaling device function is checked and communicated to the control panel
• Time consuming physical inspections are eliminated, reducing running cost
• Plant safety is increased because all devices are confirmed to be operating.
• The BEx units are designed to integrate seamlessly into the SIL 2 environment
In high risk industries such oil, gas and petrochemicals, adopting SIL 2 (Safety Integrity Level) systems is becoming the norm, in particular for the safety-critical fire and gas detection systems. While the fire and gas control panel will normally initiate automatic process shutdown procedures in the event of an alarm, the audible and visual warning devices are critical components in ensuring that personnel are warned in an emergency.
