Prakasok industrial activities. Subject to rules and procedures agreed on internal audit supervises radiator over time. 1 year but not more than 5 years. To verify once 2555 (2012)
Department of Industrial Works The rules and procedures for the approval of the Internal Audit boiler every period of more than one year but not more than five years to determine once since 2555.
Department of industrial works. On the principles and methods for approval in the internal audit of all time 1 years beyond the radiator, but not too 5 years to determine one at a time. The 2555 .