Section 21 in The Static and Mobile Pressure Vessels (Unfired) Rules, 2016
21. General.
(1)Except specifically provided in these rules, all vessels meant for storage of compressed gas shall be installed entirely above-ground, that is to say, no part of the vessel shall be buried below the ground level.(2)Vessels and first stage regulating equipment shall be located in the open.(3)Vessels shall not be installed one above the other.(4)Vessels within a group shall be so located that their longitudinal axes are parallel to each other.(5)No vessel shall be located within the bonded area of petroleum or other flammable liquid storages.(6)Sufficient space shall be provided between two vessels to permit fire-fighting operations.(7)Two or more vessels installed in batteries shall be so installed that the top surface of the vessels are on the same plane.(8)Vessels with their dished ends facing each other shall have screen walls in between them.(9)Notwithstanding anything contained in sub-rules(1) to (8) above, vessels for storage of liquified petroleum gas and other liquefied compressed gases, can be placed underground or covered by earth (mound) conforming to the national or international standard accepted by the Chief Controller and the requirements specified in Schedule III.(10)Aboveground vessel for storage of corrosive, flammable or toxic gas in liquefied state shall be provided with enclosure wall all around the ground. The minimum distance between vessel and enclosure wall shall be the diameter of the vessel or five meters, whichever is less. The ground shall be graded to form a slope away from pumps, compressors or other equipments. The height of the enclosure wall shall be thirty centimeters on the upper side and gradually increasing to maximum sixty centimeters on the lower side, at the end of which a shallow sump for collection of the spilled liquid, if any, shall be provided:Provided that no outlet shall be provided to the sump to release the spilled liquid in common or rain water drain.(11)The minimum separation distance between the vessel and the sump shall be,-(a)diameter of the vessel, in case of vessels with water capacity not exceeding forty thousand litres;(b)fifteen metres, if the water capacity of the vessels exceeds forty thousand litres.(12)A corrosion allowance of minimum 1.5 mm shall be provided for vessels made of carbon steel.(13)Operations in the licensed premises during the night shall be carried out under supervision of technically qualified and experienced personnel with adequate artificial lighting of approved type.(14)The mounded and underground vessel installation shall conform to the requirements specified in schedule III.(15)The LNG installation shall conform to the requirements specified in Schedule IV.
