Nothing in this Act shall apply to—
(a)locomotive boilers belonging to or under the control of the railways;
(b)any boiler or boiler component, —
(i)in any vessel propelled wholly or in part by the agency of steam;
(ii)belonging to, or under the control of, the Army, Navy or Air Force; or
(iii)appertaining to a sterilizer disinfector used in hospitals or nursing homes, if the boiler does not exceed one hundred liters in capacity.]