The FDIA recently did investigations regarding the operation of audible and visual alarm warnings being used in gas protected areas. Concerns were raised by our inspectors as what the correct sequence should be. It has been seen that each contractor/ consultant has a different opinion on this subject and no two gas areas were the same.
The various national standards and overseas standards were studied and they were found to be inconsistent with each other. A team from the FDIA compiled requirements to provide a solution to all the national standards.
The findings were tabulated as below.
|
Bell inside |
Siren inside |
Strobe inside
|
Siren outside
|
Strobe outside
|
|
|
1st detector activates |
On |
On |
On |
On |
|
|
2nd detector activates Timer starts |
On intermittent |
On |
On |
On |
On |
|
Timer expires Gas activates |
On solid
|
On
|
On
|
On
|
On
|
All consultants and designers are called on to follow the above to provide a unified standard of operation throughout the country.