Section 19(5) in The Static and Mobile Pressure Vessels (Unfired) Rules, 2016
(5)(a)Ammonia Horton sphere shall be subjected to first periodic inspection after two years of its installation and the inspection shall consist of detailed Non-destructive Testing of the vessel.(b)The second periodic inspection shall be carried out after three years of first inspection and shall involve Non-destructive Testing and hydro testing of the sphere.(c)Subsequent periodic inspection including Non-destructive Testing and hydro testing shall be carried out every five years.(d)If any major repair is carried out on a Horton sphere, the vessel shall be subjected to Non-destructive Testing and hydro testing in accordance with original code of construction and procedure approved by Chief Controller and the vessel shall be treated as a new vessel for subsequent periodic inspection as per the procedure noted above.(e)The Non-destructive Testing shall be as per the procedure approved by the Chief Controller.
