73A. [ Safety of water-sealed gas-holder. [Inserted by G.N. of 31st July 1964]
(1)In this rule, a gas-holder means any vessel having storage capacity of not less than 140 cubic metres and used for storage of combustible gas, wherein the gas is stored at pressure controlled by a water seal between the fixed and the moving parts of the storage vessel, and includes vessels of smaller size, in respect of which the Chief Inspector declares that in the interest of the safety of workers working near such a vessel, provisions of this rule should apply.(2)Every gas-holder,-(a)shall be of good construction, sound material, adequate strength and free from any patent defects and(b)shall be properly maintained in a safe condition.(3)No gas-holder shall be taken into use in any factory for the first time unless -(a)information giving details of gas-holder is recorded in a register in Form 13A;(b)certificate of its internal and external examination in Form 13B is obtained either from the manufacturer or from any person competent to conduct such examination; and(c)such certificate is in possession of the occupier;(4)Where in any factory two or more gas-holders are installed, each gas-holder shall be marked in a conspicuous manner with a distinguishing number or letter. If any gas-holder has two or more lifts, each lift shall also be marked with a distinguishing number or letter.(5)If any lift of the gas-holder has been in use for more than ten years before the date of final notification, then every gas- holder shall be examined externally and internally (a) within two years, if it has been examined within the last two years, (b) within one year if it has not been examined within the last two years before the aforesaid date.(6)Every gas-holder shall be thoroughly examined internally by a person competent to conduct such examination once in every period of twelve months.(7)Every gas-holder shall be examined internally by a person competent to conduct such examination at least once in every period of four years.Explanation - (a) For the purpose of this sub-rule, the internal examination of a gas-holder includes an examination of the thickness of the plates of the gas-holder including the sides and the crown by means of an electronic or other accurate device.(b)If the Chief Inspector is satisfied that the electronic devices are not available, he may permit taking samples by cutting the plates from the sides and the crown of the gas- holder:Provided that if the Chief Inspector is not satisfied that the samples are a representative sample, he may direct further samples to be cut to his satisfaction.(c)Each sample disc cut under clause (b), shall be suitably marked for identification showing date of cutting and part of the gas-holder from which it is cut. Such samples shall be kept readily available for inspection until such time as similar discs are again cut at the next inspection.(8)No gas-holder shall be repaired or demolished except under the direct supervision of a person who by his training, experience, and knowledge of the necessary precaution against risk of collapse of structure, explosion and of person being overcome by gas is competent to supervise such work.(9)A permanent register in Form 13A duly signed by the occupier or manager shall be maintained, along with a drawing to show details of construction of the gas-holder.(10)A copy of the report of persons, competent to examine gas- holders, shall be maintained in Form 13-B.]
