(3)Design and construction. - Every pressure vessel or plant used in a factory-(a)shall be properly designed on sound engineering practice;(b)shall be of good construction, sound material, adequate strength and free from any patent defects; and(c)shall be properly maintained in a safe condition :Provided that the pressure vessel or plant in respect of the design and construction of which there is an Indian standard or a standard of the country of manufacture or any other law or regulation in force, shall be designed and constructed in accordance with the said standard, law or regulation, as the case may be, and a certificate thereof shall be obtained from the manufacturer or from the competent person which shall be kept and produced on demand by an Inspector.
