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PART XIX PRESSURE VESSELS, COMPRESSORS AND REFRIGERATION
|Pressure vessel requirements
19.1 Every pressure vessel shall be :-
(a) - constructed in accordance with a code of practice approved by a reputable authority acceptable to the Chief Inspector;
(b) - manufactured under the supervision of an inspecting authority approved by the Chief Inspector;
(c) -kept clean and free from-
(i) carbonized oil or other flammable material which may ignite under working conditions, or
(ii) material which may cause corrosion, or
(iii) material which is liable to chemical reaction which may cause an uncontrolled rise in pressure; and
(d) - maintained in a safe working condition at all times.
Pressure vessel certificate
19.2 The mine manager of a mine at which a pressure vessel is used shall have in his possession a certificate, or a copy thereof, issued by the inspecting authority referred to in regulation 19.1(b) in which the code to which the vessel was manufactured is certified.
19.3 Every pressure vessel shall have a plate, securely fixed to it in a conspicuous place on the shell, bearing the following particulars-
(a) name of manufacturer,
(b) country of origin,
(c) maker's number,
(d) year of manufacture,
(e) maximum safe working gauge pressure in terms of pascals,
(f) capacity in cubic meters, and
(g) number of the code of manufacture.
Pressure vessel record
19.4 The manager shall keep a record for each pressure vessel on which shall be entered the dates on which such vessel was cleaned, examined, repaired and tested. This record shall be signed by the person in charge of such cleaning, examination, repair or test.
19.5 Every pressure vessel shall be provided with one or more suitable inspection openings, situated so that all internal surfaces and seams may be conveniently cleaned and inspected.
Manhole to be provided
19.6 Every pressure vessel, where the dimensions are such as to permit entry into the vessel, shall be provided with at least one manhole, which shall be not be less than 400 millimeters by 300 millimeters for an elliptical hole and at least 400millimeters in diameter for a circular hole: Provided that where there is no danger from internal corrosive action no manhole need to be provided.
Number and size of inspection openings
19.7 The Chief Inspector shall determine whether the number and size of the inspection openings are sufficient and he/she may require more inspection openings to be provided.
Reliable pressure gauge
19.8 Every pressure vessel shall be provided with at least one reliable pressure gauge, the dial of which shall be graduated to show gauge pressure in terms of pascals and the maximum pressure which the gauge shall be capable of registering shall not be less than the hydraulic test pressure as defined in regulation 19.22 and not more than double the maximum safe working gauge pressure of the vessel: Provided that where two or more pressure vessels with the same maximum safe working gauge pressure are connected to a common supply main, one pressure gauge fitted directly to the supply main, situated so that its reading is easily visible from any of the pressure vessels, shall be sufficient.
Safe working gauge pressure
19.9 The maximum safe working gauge pressure of the vessel shall be marked with a red line on the dial of the pressure gauge.
Provision of safety valve
19.10 Every pressure vessel shall be provided with at least one safety valve which shall be-
(a) kept locked, sealed or otherwise rendered inaccessible to any unauthorized person,
(b) set to open at or before reaching the maximum safe working gauge pressure,
(c) such as to prevent the pressure rising in excess of 10 per cent above the maximum safe working gauge pressure,
(d) attached to the pressure vessel and which shall be incapable of being shut off therefrom, except where two or more pressure vessels with the same maximum safe working gauge pressure are connected to a common supply main, one safety valve fitted directly to the supply main, situated so that it is easily visible from any of the pressure vessels, shall be sufficient: Provided that where a pressure vessel is capable of being isolated from such common supply main, the Chief Inspector may require the fitting of a fusible plug or rupturing disc to such pressure vessel,
(e) constructed of metal approved by the Chief Inspector, provided that cast iron shall not be used if the maximum safe working gauge pressure of the pressure vessel is in excess of 1 mega pascal, and
(f) arranged to discharge by means of a pipe any dangerous or toxic gas, vapour or liquid so as not to endanger the safety of persons.
Operation inability of safety valve
19.11 Where the use of a safety valve in any particular process is impracticable due to its inability to operate under all working conditions, the Chief Inspector may require or permit the use of a rupturing disc subject to such conditions as he may prescribe.
Exemption of safety valve
19.12 Where the maximum safe working gauge pressure of any steam receiver cannot be exceeded, the Chief Inspector may exempt in writing such receiver from being fitted with a safety valve.
Drains and discharges
19.13 Every pressure vessel in which liquid may collect shall be provided with a suitable drain at the lowest part of the vessel. The discharge shall be controlled by a cock or valve and shall be led to a safe place.
Liquid level indication
19.14 Every pressure vessel in which the level of the liquid in the vessel is material to safety shall be provided with a means for indicating at all times the actual level of the liquid.
Level indicator requirements
19.15 The level indicator shall be conspicuously marked, with corresponding marks on the shell of the vessel, to indicate the safe working level limits of the liquid in the vessels.
Tabular-glass type indicator guard requirements
19.16 Any indicator of the tubular-glass type shall be fitted with an efficient guard which shall not obscure the reading of the indicator and shall be constructed so as to prevent automatically the escape of any poisonous, explosive or flammable substance into the atmosphere should the glass break.
Supply pressure higher than safe working gauge pressure
19.17 Every pressure vessel which is fed from a supply, the pressure of which is higher than the safe working gauge pressure of such vessel, shall be provided with-
(a) a pressure reducing valve to reduce the supply pressure to the maximum safe working gauge pressure of the vessel, and
(b) a safety valve fitted adjacent to the low pressure side of the reducing valve and set to release at the maximum safe working gauge pressure of the vessel to prevent the pressure rising in excess of 10 per cent above the maximum safe working gauge pressure.
Two or more pressure vessels with same working pressure
19.18 Where two or more pressure vessels with the same working gauge pressure are connected to the same source of supply, one pressure reducing valve and one safety valve shall be sufficient.
Pressure vessel intended to operate under steam pressure
19.19 Every pressure vessel which is intended to operate under steam pressure and which is equipped for its operation with a removable or hinged door or cover shall be provided with an interlock or other effective means so as to prevent a rise in the pressure inside the vessel before the door or cover is in the fully closed or locked position and to prevent the release of the door or cover from the locked or closed position before the pressure inside the vessel has been reduced to atmospheric pressure.
Pressure vessel inspections
19.20 Every pressure vessel must be inspected and tested by a competent person in accordance with the provisions of these regulations.
First time inspection
19.21 Every pressure vessel in which the product of the designed working gauge pressure in kilo pascals and the capacity in cubic meters exceeds 10 but does not exceed 30, shall be inspected and tested before it is used for the first time.
Working gauge pressure exceeding 30 Mega pascals and 30 cubic meters
19.22 Every pressure vessel in which the product of the designed working gauge pressure in kilopascals and the capacity in cubic meters exceeds 30, shall be-
(a) inspected and tested before being commissioned after installation for the first time or any subsequent time, and after having been out of commission for more than two years or after major repairs and or modifications,
(b) inspected at regular intervals of not more than one year, and
(c) tested at intervals of not more than two years: Provided that where any particular working condition exists the Chief Inspector may require more frequent inspections and tests to be carried out.
Internal and external examinations
19.23 The inspection shall consist of an examination of the internal and external surfaces of the vessel and of all the fittings and appurtenances.
19.24 The test shall consist of a pressure test by water or, where the use of water is impracticable, by any other suitable liquid, to a pressure of 1.3 times the maximum safe working gauge pressure of the vessel.
Internal inspection substitution
19.25 Where the construction of the vessel is such as to preclude a thorough inspection of all internal surfaces, such as vessel jackets, the internal inspection may be substituted by a pressure test.
Non-flammable gas pressure test
19.26 Where it is impracticable to use a liquid for the above-mentioned test, the Chief Inspector may permit a test with a non-flammable gas to a pressure 1,1 times the maximum safe working gauge pressure of the vessel: Provided that the test is preceded by an internal inspection and any conditions and precautionary measures he may prescribe are complied with.
Inspection of jacketed type vessels
19.27 Notwithstanding anything to the contrary contained in this regulation, any cooking pot or similar jacketed vessel, irrespective of capacity, shall be inspected and tested as prescribed by
Suspension of operation of vessels
19.28 When at any time a pressure vessel is found to be in a condition from which danger may arise, the use of the vessel shall be suspended immediately and it shall not again be used until repairs have been carried out.
Repairs and modifications to be approved by Chief Inspector
19.29 No person shall effect any important repair and or modifications to any pressure vessel without the prior approval of the Chief Inspector.
19.30 The supply of air for any air compressor shall be drawn from the purest and coolest source available.
Compression in presence of lubricating oil
19.31 Every air compressor, in which compression takes place in the presence of lubricating oil, shall be fitted with a fusible plug as close as practicable to the outlet valve or discharge port of every stage.
Thermometer or pyrometer installation
19.32 Every air compressor having a rating exceeding 0,15 cubic meters of free air per second shall be fitted with a thermometer or pyrometer as close as practicable to the outlet valve or discharge port of every stage.
Highest temperature indication
19.33 The highest temperature allowed shall be indicated by a red mark on the scale of the thermometer of pyrometer. A person authorized by the manager shall ensure that this temperature is not exceeded and shall record in a book provided for the purpose, the highest reading on the thermometer or pyrometer observed by him during the shift: Provided that where an automatic means exist for limiting the operating temperature to a safe value, no person needs to exercise continual supervision over the compressor and no recording of the temperature needs to be done.
Rated heat extraction capacity in excess of 10 Kilowatts
19.34 Every refrigeration, cooling or freezing plant of which the manufacturer's rated heat extraction capacity is more than 10 kilowatt shall be subject to the provisions of this regulation.
Automatic pressure relief device
19.35 Every positive displacement compressor shall be provided with a pressure relief device which shall be arranged to operate automatically when the maximum safe working gauge pressure of the refrigerant is exceeded and to discharge so as not to endanger the safety of persons.
Pressure limit device
19.36 A pressure limiting device shall be provided between the compressor and the stop valve on the discharge side and this device shall stop the operation of the compressor at or below the maximum safe working gauge pressure.
Reliable pressure gauge
19.37 A reliable pressure gauge shall be provided to indicate the discharge gauge pressure of the compressor.
Trap drier or interceptor
19.38 A trap, drier or interceptor shall be provided on the suction side of the compressor except in the case of wet compression when the compressor shall be fitted with a safety head.
No control valve inside cool-room
19.39 No control valve shall be situated inside any cool-room.
Doors to open from inside
19.40 Every door of any cool-room, including any associated air lock, shall be capable of being opened easily from the inside.
19.41 Additional doors shall be provided to every machine room and passage to facilitate the escape of any person, if such doors are deemed necessary by the Chief Inspector.
First aid treatment
19.42 Instructions in the first aid treatment of persons suffering from gassing effects shall be posted up outside every entrance to refrigeration, cooling or freezing plant.
Hose to be connected to water supply
19.43 At the entrance to the plant, other than a plant in which fluorinated hydro-carbons are used as the refrigerant, there shall be provided and kept readily accessible an adequate length of hose permanently connected to a water supply and two suitable gas masks, which shall be examined at least once in every six months by a competent person.
Appointment of competent person
19.44 The manager shall appoint, in writing, a competent person or person who shall examine and test at least once in every three months the entire refrigeration, cooling or freezing plant and all its component and auxiliary parts: Provided that all pressure vessels containing liquid refrigerant shall be inspected and tested in accordance with the provisions of regulation 18.38-18.41.
Refrigerator record book
19.45 The manager shall provide a book to be known as the Refrigerator Record Book in which shall be recorded the following particulars-
(a) the name and address of the manufacturer of the plant,
(b) the manufacturer's maximum rated capacity in kilowatts,
(c) the refrigerant used,
(d) the maximum safe working gauge pressure,
(e) the condensing and evaporating temperature at which the rated capacity is calculated,
(f) the number of cylinders, the bore, the stroke and the speed of the compressor in revolutions per minute,
(g) the manufacturer's maximum rated speed of the compressor in revolutions per minute,
(h) the type of compressor,
(i) the type of condensor,
(j) the type of driving unit,
(k) the power of the driving unit or, for an absorption system, the steam consumption per hour or the kilowatt rating, and
(l) whether direct coupled or not.
(m) the name or names of the competent person or persons appointed by him to carry out the examination and test,
Safety devices to be checked
19.46 At the examination referred to in regulation 18.60, the competent person appointed shall check all safety devices installed to ensure that they are in proper working order and shall satisfy himself that the entire plant is in safe condition.
19.47 A report of every examination carried out in terms of regulation 18.60 and of any repair or alteration carried out shall be recorded and signed without delay in the Refrigerator Record Book by the person making such examination, repair or alteration.
Defects to be reported to the manager
19.48 The person who makes an examination shall record and sign the result of such examination in the Refrigerator Record Book. He/she will immediately report to the mine manager, any defects discovered.