Section 56 in The West Bengal Factories Rules, 1958
56. Pressure Vessel and Plant.
(1)In this rule (a)'Design pressure' means the maximum pressure that a pressure vessel or plant is designed to withstand sagely 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 sude under this rule and is determined by the technical requirements of the process;(c)'Plant' means a system of piping that is connected to a pressure vessel and is used to contain any gas, vapour or liquid under pressure greater than the atmosphere, and includes the pressure vessel; and(d)'Pressure vessel' means a vessel that may be used for containing storing, distributing, transferring, distilling, processing or otherwise handing any gas, vapour or liquid under pressure greater than the atmospheric pressure and includes any pipeline, fitting or other equipment attached thereto or used in connection therewith.(2)Nothing in this rule shall apply to-(a)vessels having internal diameter not exceeding 150 mm. and a capacity not exceeding 145 litres;(b)vessels made of ferrous materials having an internal operating pressure not exceeding one kilogram per square centimeter;(c)steam boiler, steam and feed pipes and their fittings coming under the purview of Indian Boilers Act, 1923 (5 of 1923);(d)metal bottles or cylinder or pressure vessels used for storage or transport of compressed gases or liquid or dissolved gases under pressure covered by the Gas Cylinder Rules, 1981 and the Static and Mobile Pressure Vessels (Unfired) Rules, 1981 framed under the Indian Explosives Act, 1884 (4 of 1884);(e)vessels in which internal pressure is due solely to the static head of liquid;(f)vessel with a nominal water capacity not exceeding 500 litres connected in a water-pumping system containing air that is compressed to serve as a cushion;(g)vessels for nuclear energy application;(h)refrigeration plant having a capacity of 3 tons or less of refrigeration in 24 hours; and(i)working cylinders of steam engines or prime movers, feed pump and steam trapes, turbine casings, compressor cylinders, steam separators or dryers, steam strainers, steam de-super-heaters, [xxxx] [Omitted by West Bengal Factories (Amendment) Rules, 1991.], air receivers for fire sprinkler installations, air receivers of monotype machines provided the maximum working pressure of the air receiver does not exceed 1.33 kg. Per sq.cm. (20 lbs./sq.in) and the capacity [85] [Substituted by ibid.] litres (3 cu.ft), air receivers of electrical circuit breakers, air receivers or electrical relays, air vessels on pumps, pipe coils, accessories of instruments and appliances, such as cylinders and piston assemblies used for operating relays and interlocking type of guards, vessels with liquids subjected to static head only, and hydraulically operating cylinders other than any cylinder communicating with an air loaded accumulator.(3)Every pressure vessel or plant used in a factory-(a)shall be properly designed on sound engineering practice;(b)shall be of construction, sound material, adequate strength and free from any patent defect; and(c)shall be properly maintained in a safe condition:Provided that the pressure vessel or plant in respect of the design and construction on which there is an Indian standard of the country of manufacture or any other law or regulation 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 a competent person which shall be kept and produced on demand by an Inspector.(4)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 used be set to operate at the maximum permissible working pressure and the additional device shall be set to discharge at a pressure not more that 5 per cent in excess of the maximum permissible working pressure;(b)a suitable pressure gauge with a dial range not less than 1.5 times the maximum permissible working pressure, easily visible and designed to show at all time the correct internal pressure and marked with a prominent red mark at the maximum permissible working pressure of the pressure vessel;(c)a suitable attachment for fixing a standard 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 may be isolated from other pressure vessels of 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 substances that may collect in the pressure vessel;Provided that it shall be sufficient for the purpose of this sub-rule if the safety valve or pressure device, the pressure gauge and the stop valve are mounted on a pipeline 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 to be fitted on the pressure lead immediately adjacent to the range of pressure vessels provided they cannot be isolated:Provided further that in case where owing to the nature of the process or the action of the contents of the vessels a pressure gauge or safety valve or both cannot work reliably, a tested and reliable working thermometer with a sufficient large scale, on which shall be clearly marked the maximum permissible temperature in the vessel or pyrometers or rupture discs in addition to the pressure gauge and safety valve may be fitted as may be directed by the Chief Inspector.(5)(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 vessel with any other source or 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 vessel in the event of failure of the reducing valve or device, at least one suitable safety valve or other pressure, relieving device of adequate capacity sufficient to release of the steam, vapour or gas without undue pressure rise as determined by the pressure at the source of supply and the size of the pipe connecting the source of supply, shall be fitted close to the reducing valve on the low pressure side.(6)(a)No new pressure vessel or plant shall be taken into use in a 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 6 months or which has undergone alterations or repairs shall be taken into use in a factory, unless it has been the roughly examined by a competent person externally, and internally, if practicable, and has been hydrostatically tested by the competent person at a pressure which shall be 1 .5 times the maximum permissible working pressure;Provided, however, that the pressure vessel or plant Which is so designed and constructed that it cannot be safely filled with water or liquid or is used in service where even 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, subject to the condition that-(i)where the source of pressure is higher than the test pressure. precaution against over-pressurisation of vessel or plant under test shall be taken by the use of suitable reducing valve, pressure gauge and safety valve of adequate size:(ii)steps shall be taken to ensure that people are not likely to be injured in the event of bursting either by containing the vessel under test within a blast pit, or by retaining wall, or by ensuring that such personnel are adequately protected; and(iii)the vessel under test should not be approached for close inspection until after the test the pressure has been reduced:Provided further that the pressure vessel or plant which is lined with glass shall be tested hydrostatically or pneumatically as required at a pressure not less than the design pressure or maximum permissible working pressure, as the case may be.Explanation- Design pressure shall be not less than the maximum permissible working pressure and shall take into account the possible fluctuation 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 a competent person a certificate specifying the design pressure or maximum permissible working pressure thereof, and starting the nature of tests to which the pressure vessel or plant and its fitting (if any) have been subjected, and every pressure vessel or plant so used in a factory shall be conspicuously 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)Every pressure vessel or plant in service shall be thoroughly examined by a competent person-(a)externally, once in every period of six months;(b)internally, once in very period of twelve months;Provided that if by reason of the construction of a pressure vessel or plant, a thorough 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;(c)hydrostatically tested once in every period of four years:Provided that in respect of a pressure vessel or plant within 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 the pressure vessel or plant cannot be hydrostatically tested as required in clauses (b) and (c) of this sub-rule, a thorough 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 thorough systematic non-destructive test, like ultrasonic test, to detent defects of all parts shall be carried out.(8)(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 per cent 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 twenty 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 effect its strength or safety have been carried out, shall be tested before use to at least 1.5 times its maximum permissible working pressure.(9)(a)A report of the result of every examination or test, carried out, shall be completed in the prescribed Form No.9 within seven days of completion of the work 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.(b)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 form his observations, findings and conclusions with other relevant remarks with reasons and may authorise 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.(c)The competent persons making report of any examination under this rule, shall within seven days of the completion of the examination, send 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 and other safety measure is taken.(d)If a competent person falls to make a thorough examination as required by this rule or makes a report which is false or deficient in any material particular or falls to send to the Inspector a copy of the report as required by clause (C) of this sub-rule, he shall be guilty of an offence.(10)Where the report of any examination under this rule specifies 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.(11)If the Chief Inspector is not satisfied as to the competence of the person employed to make the examination or as to the thoroughness of the examination, he may require the pressure vessel or plant to be re-examined by a person nominated by him by an order in writing.(12)(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.]
