NBIC, NB-23, the National Board Inspection Code, addresses Test Frequency in part RB-3500, In service inspection.
Boilers <400 psi, every 6 months
Boilers >400 psi, every 36 months
High Temp Water Boilers, 12 months
Low Pressure Heating Boilers (15 psi) quarterly manual check (lift lever) & annual test.
Water Heaters, 2 months
Pressure Vessels & Piping, depends on application:
Steam, 12 months
Air/Dry, Clean Gas, 36 months
Propane & Refrigerant, 60 months
All others, per Inspection History
Note: ASME Sec. VII, Recommended Care of Power Boilers has 12 months on Boiler Proper and 6 months to 24 months on aux PRVs. ASME Sec I, Part PVG requires Organic Vapor Generators every 12 months.
JAlton J. Alton Cox
President
DeLuca Test Equipment