.-(1) Gas cylinders designed and approved for filling with a particular gas shall not be used for filling with any other gas unless specific approval is obtained from the Chief Controller except that:-(a)inert gases, oxygen and compressed air cylinders made to the same specification and design may be converted from one gas to another after fitting with appropriate valve and painting with appropriate identification colour without prior permission from Chief Controller, with approval of the cylinder owner.(b)proper records of such conversions shall be maintained by the gas filler for examination of Chief Controller or Controller as and when needed.(2)Any person desiring for conversion approval shall submit to Chief Controller the following:-(i)documentary evidence indicating that the cylinders have been purchased by him;(ii)an authenticated copy of letter permitting filling of the cylinders in the past;(iii)a statement in duplicate, showing manufacturer's serial numbers of the cylinders in ascending order;(iv)a certificate to the effect that the cylinder(s) had not been converted to any other gas service in the past;(v)scrutiny fee as specified in Schedule V.
