Class A & B Divisions

What is Class 'A' & 'B' Divisions? 

'A' Class Divisions are Those Divisions Formed by Bulkhead & Decks which Comply with the given Criteria below:

1- They are Constructed of Steel Or other similar material. 

2- They are Suitability stiffened. 

3- They are insulated with approved non combustible materials such that the average temperature of the unexposed side will not rise more than 140°C above the original temperature, nor will the temperature at any point, including any joint rise more than 180°C above the original temperature with in the given time below :

Class 'A-60' - 60 min

Class 'A-30' - 30 min

Class 'A-15' - 15 min

Class 'A-0'   - 00 min

4- They are so constructed as to be capable of preventing the passage of smoke & flame to the end of the one hour standard fire test. 

5- It meets the requirements for integrity & temperature rise. 

'B' Class Divisions are those divisions formed 

by Bulkheads, Decks, Ceilings or Linings which comply with the following criteria :

1- They are Constructed of approved Non-combustible material and all materials used in the construction and erection of 'B' Class Divisions are non combustible, with the exception that combustible veneers may be permitted provided, they meet other appropriate requirements. 

2- They have an insulation valve such that average temperature of the unexposed side will not rise more than 140°C above the original temperature, nor will the temperature at any one point, including any joint, rise more than 225°C above the original temperature with in time listed below :

Class 'B-15 - 15 min

Class 'B-0   - 00 min

3- They are so constructed as to be capable of preventing the passage of flame to the end of the first half hour of the standard fire test. 

4- It meets the requirements for integrity & temperature rise.