C. 23. Pressure Vessels Flashcards
What shall the manager of a mine or works where a pressure vessel is used be in possession of?
23.2.1 The manager of a mine or works 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 23.1.2 in which the code to which the vessel was manufactured is certified.
How shall every pressure vessel be according to the regulations?
- 1 Every pressure vessel-
- 1.1 shall be constructed in accordance with a code of practice approved by the Chief Inspector, or where no approved code exists for any particular vessel, its construction shall be approved by the Chief Inspector.
- 1.2 shall be manufactured under the supervision of an inspecting authority approved by the Chief Inspector.
- 1.3 shall be kept clean and free from-
(a) carbonised oil or other flammable material which may ignite under working conditions; or
(b) material which may cause corrosion; or
(c) material which is liable to chemical reaction which may cause an uncontrolled rise in pressure; and - 1.4 shall be maintained in a safe working condition at all times.
What particulars shall be on a plate, securely fixed to every pressure vessel?
- 3 Every pressure vessel shall have a plate, securely fixed to it in a conspicuous place on the shell, baring he folliwng 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 metres; and
(g) number of the code of manufacture.
What shall the manager keep record of on any pressure vessel?
23.4 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 and test.
What does the regulation stipulate about inspection openings for every pressure vessel?
- 5.1 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.
- 5.2 Every pressure vessel where the dimensions are such as to permit of entry into the vessel, shall be provided with at least one manhole, which shall not be less than 400 millimetres by 300 millimetres for an elliptical hole and at least 400 millimetres in diameter for a circular hole: Provided that where there is no danger from internal corrosive action no manhole need be provided.
- 5.3 The Principal Inspector of Mines shall determine whether the number and size of the inspection openings are sufficient and he may require more inspection openings to be provided.
What does the regulation stipulate about the pressure gauges of every pressure vessel?
- 6.1 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 23.12.5 and not more than double the maximum safe working gauge pressure of the vessel: Provided that where 2 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.
- 6.2 The maximum safe working gauge pressure of the vessel shall be clearly marked with a red line on the dial of the pressure gauge.
What does the regulation stipulate about the safety valve of every pressure vessel?
- 7.1 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 unauthorised 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 percent 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 2 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 Principal Inspector of Mines may require the fitting of a fusible plug or rupturing disc to such pressure vessel;
(e) constructed of metal approved by the Principal Inspector of Mines, provided that cast iron shall not be used if the maximum safe working gauge pressure of the pressure vessel is in excess of 1 megapascal; 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. - 7.2 Where the use of a safety valve in any particular process is impracticable due to its inability to operate under all working conditions, the Principal Inspector of Mines may require or permit the use of a rupturing disc subject to such conditions as he may prescribe.
- 7.3 Where the maximum safe working gauge pressure of any steam receiver cannot be exceeded, the Principal Inspector of Mines may exempt in writing, such receiver from being fitted with a safety valve.
What does the regulation stipulate about level indicators for every pressure vessel?
- 8 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.
- 9.2 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 vessel.
- 9.3 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.
What shall every pressure vessel which is used is fed from a supply, the pressure of which is higher than the safe working gauge pressure of such vessel be provided with?
- 10.1 Every pressure vessel which is used 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 percent above the maximum safe working gauge pressure. - 10.2 Where 2 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.
How shall every pressure which is equipped with removable or hinged doors or covers be operated?
23.11 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 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.
What examinations and tests shall be done on every pressure vessel?
- 12.1 The person appointed in terms of regulations 2.13.1, 2.13.2 or 2.13.3 shall ensure that every pressure vessel is inspected and tested in accordance with the provisions of this regulation.
- 12.2 Every pressure vessel in which the product of the designed working gauge pressure in kilo-pascals and the capacity in cubic metres exceeds 10 but does not exceed 30, shall be inspected and tested before it is used for the first time.
- 12.3 Every pressure vessel in which the product of the designed working gauge pressure in kilopascals and the capacity in cubic metres exceeds 30, shall be-
(a) inspected and tested before being commissioned after installation for the first time or any subsequent time, after having been out of commission for more than 2 years or after major repairs;
(b) inspected at regular intervals of not more than one year; and
(c) tested at regular intervals of not more than 2 years: Provided that where any particular working condition exists the Principal Inspector of Mines may require more frequent inspections and tests to be carried out. - 12.4 The inspection shall consist of an examination of the internal and external surfaces of the vessel and of all the fittings and appurtenances.
- 12.5 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.
- 12.6 Where the construction of the vessel is such as to preclude a thorough inspection of all the internal surfaces, such as vessel jackets, the internal inspection may be substituted by a pressure test.
- 12.7 Where it is impracticable to use a liquid for the above-mentioned test, the Principal Inspector of Mines may permit a test with a non-flammable gas to a pressure of 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.
- 12.8 Notwithstanding anything to the contrary contained in this regulation, any cooking pot and similar jacketed vessel, irrespective of capacity, shall be inspected and tested as prescribed by regulation 23.12.3.
What must happen when any problems are found when examining or testing any pressure vessel?
- 13.1 When it appears from an examination or test that a pressure vessel can no longer be used with safety at the manufacturers intended maximum working gauge pressure, the Principal Inspector of Mines may fix a new maximum working gauge pressure at which the vessel may continue to be used and he shall require the new reduced pressure to be marked on the plate provided in terms of regulation 23.3 and no person shall require or permit such vessel to be used at a higher pressure.
- 13.2 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.
- 13.3 No person shall effect any important repair to any pressure vessel without the prior approval of the Principal Inspector of Mines.
How shall every pressure vessel be constructed?
23.1.1 shall be constructed in accordance with a code of practice approved by the Chief Inspector, or where no approved code exists for any particular vessel, its construction shall be approved by the Chief Inspector.
How shall every pressure be manufactured?
23.1.2 shall be manufactured under the supervision of an inspecting authority approved by the Chief Inspector.
Every pressure vessel shall be kept clean and free from what?
- 1.3 shall be kept clean and free from-
(a) carbonised oil or other flammable material which may ignite under working conditions; or
(b) material which may cause corrosion; or
(c) material which is liable to chemical reaction which may cause an uncontrolled rise in pressure; and
