(1)A certificate authorising the use of a boiler shall cease to be in force,—(a)on the expiry of the period for which it was granted; or(b)when any accident occurs to the boiler; or(c)when the boiler is moved, except a vertical boiler, the heating surface of which is less than twenty square metres, or a portable or vehicular boiler; or(d)save as provided in section 17, when any structural alteration, addition or renewal is made in or to the boiler; or(e)in case the Chief Inspector in any particular case so directs, when any structural alteration, addition or renewal is made in or to any steam-pipe attached to the boiler; or(f)on the communication to the owner of the boiler of an order of the Chief Inspector or the Inspector prohibiting its use on the ground that it or any boiler components attached to it is in a dangerous condition.
