(1)Interpretation. - In this rule.(a)'design pressure' means the maximum pressure that a pressure vessel or plant is designed to withstand safely when operating normally.(b)'maximum permissible working pressure' is the maximum pressure at which a pressure vessel or plant is permitted to be operated or used under this rule and is determined by the technical requirements of the process;(c)[ Omitted] [Clause (c) omitted by SRO No. 1149/2001 dt. 28-12-2001.](d)'Pressure Vessel' means vessels that may be used for containing, storing, distributing, transferring, distilling, processing or otherwise handling any gas, vapor or liquid under pressure greater than the atmospheric pressure and includes any pipe line fitting or other equipment attached thereto for used on connection therewith ; [Amended by G.O. (Rt) No.1786/79 L&H dt. 17-12-1979] and(e)[ Omitted] [Clause (e) omitted by SRO No. 766/95, dt. 07-06-1995.](2)Exceptions. - Nothing in this rule shall apply to -(a)Vessels made of ferrous materials having an internal operating pressure not exceeding 1 Kg/cms 2 (15 lbs/Sq.inch) ;(b)Steam boilers, steam and feed pipes and their fittings coming under the purview of Indian Boilers Act, 1923 (V of 1923) ;(c)metal bottles or cylinders used for storage or transport of compressed gases or liquified or dissolved gases under pressure covered by the Gas Cylinder Rules, 1940 framed under the Indian Explosive Act, 1884 (IV of 1884);(d)vessels in which internal pressure is due solely to the static head of liquid ;(e)vessels with a nominal water capacity not exceeding 500 liters connected in a water-pumping system containing air that is compressed to serve as a cushion;(f)vessels for nuclear energy application ;(g)Refrigeration plant having a capacity of 3 tones or less or refrigeration in 24 hours; and(h)Working cylinders of steam engines or prime movers, feed pumps and steam traps; turbine casings; compressors cylinders; steam separations or dyers; steam strainers; stream de-super heaters; oil separators; air receivers for fire sprinkler installations; air receivers or monotype machines provided the maximum working pressure of the air receiver does not exceed 1.33 kg.f/cm 2 (20lb/sq.inc.) and the capacity 84.95 liters (3cu.ft.); air receivers of electrical circuit breakers; air receivers of electrical relays; air vessels on pumps, pipe coils accessories of instruments and appliances, such as cylinders and piston assemblies used for operating relays and inter-locking type of guards; vessels with liquids subjected to static head only; and hydraulically operating cylinders other than any cylinder communicating with an air and accumulator.(3)Design and construction. - Every pressure vessel or plant used in 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 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 maybe, and a certificate there of shall be obtained from the manufacturer or from the competent person which shall be kept and produced on demand by an Inspector.(4)Safety Devices. - Every pressure vessel shall be fitted with -(a)a suitable safety valve or other effective pressure relieving device of adequate capacity to ensure that the maximum permissible working pressure of the pressure vessel shall not be exceeded. It shall be set to operate at a pressure not exceeding the maximum permissible working pressure and when more than one protective device is provided, only one of the devices need be set to operate at the maximum permissible working pressure and the additional device shall be set to discharge at a pressure not more than 5% in excess of the maximum permissible working pressure.(b)a suitable pressure gauge with a dial range not less than 1 times the maximum permissible working pressure, easily visible and designed to show at all times the correct internal pressure and marked with a prominent red mark at the maximum permissible working pressure of the pressure vessel;(c)a suitable nipple and globe valve connected for the exclusive purpose of attaching a test pressure gauge for checking the accuracy of the pressure gauge referred to in clause (b) of this sub-rule;(d)a suitable stop valve or valves by which the pressure vessel maybe isolated from other pressure vessels or plant or source of supply of pressure. Such a stop valve or valves shall be located as close to the pressure vessel as possible and shall be easily accessible; and(e)a suitable drain cock or valve at the lowest part of the pressure vessel for the discharge of the liquid or other substance that may collect in the pressure vessel;Provided that it shall be sufficient for the purposes of this sub-rule if the safety valve or pressure relieving device, the pressure gauge and the stop valve are mounted on a pipe line immediately adjacent to the pressure vessel and where there is a range of two or more similar pressure vessels served by the same pressure lead, only one set of such mountings need be fitted on the pressure lead immediately adjacent to the range of pressure vessels, provided they cannot be isolated.(5)Pressure Reducing Devices. - (a) Every pressure vessel which is designed for a working pressure less than the pressure at the source of supply, or less than the pressure which can be obtained in the pipe connecting the pressure vessels with any other source of supply, shall be fitted with a suitable pressure reducing valve or other suitable automatic device to prevent the maximum permissible working pressure of the pressure vessel being exceeded.(b)To further protect the pressure vessels in the event of failure of the reducing value or device, at least one safety valve having a capacity sufficient to release all the steam, vapour or gas without under pressure rise as determined by the pressure at the source supply and the size of the pipe connecting the source of supply, shall be fitted on the low pressure side of the reducing valve.(6)Pressure vessel or plant being taking into use. - (a) no new pressure vessel or plant shall be taken into use in factory after coming into force of this rule unless it has been hydrostatically tested by a competent person at a pressure at least 1.3 times the design pressure, and no pressure vessel or plant which has been previously used or has remained isolated, or idle for a period exceeding two months or which has undergone alterations or repairs shall be taken into use in a factory unless it has been thoroughly examined by a competent person externally, and internally, if practicable, and has been hydrostatically tested by the competent person at pressure which shall be 1.5 times the maximum permissible working pressure.Provided, however, that the pressure vessel or plant which so designed and constructed that it cannot be safely filled with water or liquid or is used in service when even some traces of water cannot be tolerated, shall be pneumatically tested at pressure not less than the design pressure or the maximum permissible working pressure as the case may be:Provided further that the pressure vessel or plant which so lined with glass shall be tested hydrostatically or pneumatically as required at a pressure not less than the designed pressure or maximum permissible working pressure as the case may be. Design pressure shall be not less than the maximum permissible working pressure and shall take into account the possible fluctuations of pressure during actual operation;(b)No pressure vessel or plant shall be used in a factory unless there has been obtained from the maker of the pressure vessel or plant or from the competent person a certificate specifying the design pressure or maximum permissible working pressure thereof, and stating the nature of tests to which the pressure vessel or plant and its fittings (if any) have been subjected, and every pressure vessel or plant so used in a factory shall be marked so as to enable it to be identified as to be the pressure vessel or plant to which the certificate relates and the certificate shall be kept available for perusal by the inspector;(c)No pressure vessel or plant shall be permitted to be operated or used at a pressure higher than its design pressure or maximum permissible working pressure as shown in the certificate.(7)In service test and examinations. - Every pressure vessel or plant in service shall be thoroughly examined by competent person-(a)externally, once in every period of six months(b)internally, once in every period of twelve months;If by a reason of the construction of a pressure vessel or plant, a through internal examination is not possible, this examination may be replaced by a hydrostatic test which shall be carried out once in every period of two years.Provided that for a pressure vessel of plant in continues process which cannot be frequently opened the period of internal examinations may be extended to four years; and(c)Hydrostatical test once in every period of four years;Provided that in respect of a pressure vessel or plant with thin walls such as sizing cylinder made of copper or any other non-ferrous metal, periodic hydrostatic test may be dispensed with subject to the condition that the requirements laid down in sub-rule 8 are fulfilled:Provided further that when it is impracticable to carry out thorough external examination of any pressure vessel or plant every six months as required in clause (a) of this sub-rule, or if owing to its construction and use a pressure vessel or plant cannot be hydrostatically tested as required in clauses (b) and (c) of this sub-rule, a through external examination of the pressure vessel or plant shall be carried out at least once in every period of two years, and at least once in every period of four years, a through systematic, non-destructive test like ultrasonic test for metal thickness or other defects of all parts the failure of which might lead to eventual rupture of the pressure vessel or plant shall be carried out.(d)The hydrostatic test, pressure to be carried out for the purpose of this rule shall be 1.25 times the design pressure or 1.5 times the maximum permissible working pressure whichever is less.(8)Thin walled pressure vessel or plant. - (a) In respect of any pressure vessel or plant of thin walls such as sizing cylinder made of copper or any other non-ferrous metal the maximum permissible working pressure shall be reduced at the rate of 5 percent of the original maximum permissible working pressure for every year of its use after the first five years and no such cylinder shall be allowed to continue to be used for more than 20 years after it was first taken into use;(b)If any information as to the date of construction, thickness of walls, or maximum permissible working pressure is not available, the age of such pressure vessel or plant shall be determined by the competent person in consultation with the Chief Inspector from the other particulars available with the manager ;(c)Every new and second hand pressure vessel or plant of thin walls to which repairs likely to affects its strength or safety have been carried out, shall be tested before use at least 1.5 times its maximum permissible working pressure.(9)Report by Competent person. - (a) If during any examination any doubt arises as to the ability of the pressure vessel or plant to work safely until the next prescribed examination, the competent person shall enter in the prescribed register his observations, findings and conclusions with other relevant remarks with reasons and may authorize the pressure vessel or plant to be used and kept in operation subject to a lowering of maximum permissible working pressure, or to more frequent or special examination or test, or subject to both of these conditions ;(b)A report of the result of every examination or test carried out shall be completed in the prescribed Form No. 8 and shall be signed by the person making the examination or test, and shall be kept available for perusal by the inspector at all hours when the factory or any part thereof is working;(c)Where the report of any examination under this rule specified any condition for securing the safe working of any pressure vessel or plant, the pressure vessel or plant shall not be used unless the specified condition is fulfilled;(d)The competent person making report of any examination under this rule, shall within seven days of the completion of the examination, sent to the Inspector a copy of the report in every case where the maximum permissible working pressure is reduced or the examination shows that the pressure vessel or plant or any part thereof cannot continue to be used with safety unless certain repairs are carried out or unless any other safety measure is taken.(10)Application of other laws. - (a) The requirements of this rule shall be in addition to and without any prejudice to and not in derogation of the requirements of any other law in force;(b)Certificates or reports of any examination, or test of any pressure vessel or plant to which sub-rules 7 to 9 do not apply, conducted or required to be conducted under any other law in force and other relevant record relating to such pressure vessel or plant, shall be properly maintained as required under the said law and shall be produced on demand by the Inspector.
