BS-5793-4-1987 IEC-60534-4-1982.pdf

BRITISH STANDARD BS 5793-4: 1987 IEC 534-4: 1982 (including Amendment No. 1 August 1986) Industrial-process control valves Part 4: Specification for inspection and routine testing UDC 66.025:621.646.3:681.533.3:004.58:620.1 BS 5793-4:1987 This British Standard, having been prepared under the direction of the Industrial-process Measurement and Control Standards Committee, was published under the authority of the Board of BSI and comes into effect on 30 October 1987 © BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference PCL/1 Draft for comment 80/21854 DC ISBN 0 580 16246 X Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Industrial-process Measurement and Control Standards Committee (PCL/-) to Technical Committee PCL/1, upon which the following bodies were represented: British Coal British Gas Corporation British Pressure Gauge Manufacturers Association Department of Energy (Gas and Oil Measurement Branch) Department of Trade and Industry (National Weights and Measures Laboratory) Energy Industries Council Engineering Equipment and Materials Users Association GAMBICA (BEAMA Ltd.) Health and Safety Executive Institution of Gas Engineers The following bodies were also represented in the drafting of the standard, through subcommittees and panels: British Chemical Engineering Contractors Association British Valve Manufacturers Association Ltd. Electricity Supply Industry in England and Wales Amendments issued since publication Amd. No.Date of issueComments BS 5793-4:1987 © BSI 08-1999i Contents Page Committees responsibleInside front cover National forewordii 1Scope1 2Information supplied by the purchaser1 3Inspection1 4Pressure and leak tests2 5Performance tests5 Table 1 Hydrostatic test pressure3 Table 2 Duration of hydrostatic tests of shell3 Table 3 Maximum seat leakage for each leakage class5 Table 4 Class VI: Leakage factors6 Publication referred toInside back cover BS 5793-4:1987 ii © BSI 08-1999 National foreword This Part of BS 5793 has been prepared under the direction of the Industrial-process Measurement and Control Standards Committee. It is identical with IEC Publication 534-4:1985 “Industrial-process control valves Part 4: Inspection and routine testing ” including Amendment No. 1 published by the International Electrotechnical Commission (IEC). Terminology and conventions. The text of the international standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. In British Standards it is current practice to use the symbol “mL” for millilitres rather than “ml”. The reference to “other parts of IEC Publication 534” in clause 1 should be read as “other Parts of BS 5793”. Cross-reference. The Technical Committee has reviewed the provisions of IEC Publication 534-1, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. BS 5793-4:1987 © BSI 08-19991 1 Scope This standard specifies the requirements for the inspection and routine testing of control valves manufactured in conformity with the other parts of IEC Publication 534. When specified, the inspection and test requirements shall be taken from this part in conjunction with any additional information required by Sub-clause 2.1 or a code of practice stated by the purchaser. This standard does not apply to the types of control valves where radioactive service, fire safety testing, or other hazardous service conditions are encountered. If a standard for hazardous service conflicts with the requirements of this standard, the standard for hazardous service shall take precedence. This standard is applicable only to valves with pressure ratings not exceeding PN 100 (Class 600). 2 Information supplied by the purchaser 2.1 If test conditions outside the requirements of this standard are required, they shall be the subject of agreement between manufacturer and purchaser. 2.2 Certain clauses in this standard permit alternative test requirements. The purchaser shall inform the manufacturer, preferably at the time of enquiry, and certainly in the purchase order, of the following: whether inspection by the purchaser at the manufacturers plant is required; whether any special performance tests are required; whether any special material tests are required; whether any supplementary inspection requirements for castings, forgings or welded assemblies and associated test certificates are required; whether repair of defects is prohibited, or whether records of such repairs are required; whether a test fluid other than water at ambient temperature is required and, if so, the precise details of any alternative method and/or fluid; whether or not control valve test certificates are required. 3 Inspection 3.1 Inspection at manufacturers plant If specified in the purchase order, the control valve shall be inspected by the purchasers inspector (or his appointed representative) accompanied by an authorized representative of the manufacturer at the place of manufacture. This inspection shall be so conducted as not to interfere unnecessarily with the manufacturers programme. The inspector shall be allowed access at all reasonable times, but only to those parts of the manufacturers plant which are concerned with the assembly and testing of the control valves. The inspector shall be afforded all reasonable facilities for checking that the control valves are manufactured in accordance with the requirements of this standard and the purchase order. When inspection by the purchaser has been stipulated, the control valve manufacturer shall normally give notice of the availability of the control valves for inspection or test as agreed with the purchaser. 3.1.1 Scope of inspection by the purchaser Normal inspection by the purchaser shall be limited to: a) visual examination of any finished component at the assembly stage; b) visual and dimensional check of the finished control valve to ensure compliance with purchase order specifications of those dimensions which will affect installation of the control valve in the purchasers facility; c) witnessing of shell pressure tests, as specified in Clause 4 and, where applicable, seat pressure tests as referenced in Sub-clause 5.4; d) witnessing of performance tests, where applicable, as specified in Clause 5. NOTE Any part of the inspection procedure may be waived by the inspector. 3.1.2 Inspection of purchased components Should the manufacturer obtain component parts such as castings, forgings, etc., from some other supplier, similar facilities for inspection of these components may be given to the purchasers inspector by special prior arrangement with the manufacturer. BS 5793-4:1987 2 © BSI 08-1999 3.1.3 Certificate of compliance The manufacturer, when so requested, shall supply a certificate stating that the control valve and the control valve parts comply in all respects with the requirements of this standard and the purchase order. This certificate may be accepted at the option of the purchaser in lieu of normal inspection and test at the manufacturers plant. 3.2 Inspection of materials Physical tests and chemical composition of materials used in the construction of the control valve shall be as specified in the various material specifications referred to in the specification of the control valve or in the purchase order. Requirements for certificates of compliance or certified physical and chemical test results (which will not be supplied as standard) shall be specified in the purchase order, and shall be the subject of agreement between manufacturer and purchaser. 3.3 Supplementary inspection When specified in the enquiry and the purchase order, supplementary tests, such as magnetic particle, radiographic examination or other tests, shall be the subject of negotiation between manufacturer and purchaser. If copies of the relevant test certificates are required, this should also be stated in the enquiry and the purchase order. 3.4 Repair of shell defects Defects in the shell castings of a control valve may be repaired unless otherwise specified in the purchase order or prohibited by a specified code of practice. Good workmanship is essential and welding operations shall be properly executed with particular attention to such aspects as: 1) weld preparation, 2) preheating, 3) method of welding and 4) post-weld heat treatment. NOTEIn order that a satisfactory procedure can be specified to ensure good welding practice, it is recommended that some national standard or recognized procedure shall be agreed between purchaser and manufacturer and referenced in the purchase documents. 3.5 Use of rejected materials Any completed control valves, raw materials or finished components (whether made by the manufacturer or purchased from other suppliers) which have been rejected by the purchasers inspector, shall not be reused after repair unless approved by the purchasers inspector or as provided in Sub-clause 3.4. 3.6 Protective coatings Unpainted surfaces of control valves may be protected by an easily removable rust preventative provided this is removed from all seating faces before test. Control valves shall normally be tested before painting but painted control valves or components from stock may be retested without removal of paint. Where a permanent lining, such as glass, polytetrafluorethylene, etc., is specified, the purchaser may further specify a pressure test on the shell prior to lining in addition to the hydrostatic test on the shell following lining. 4 Pressure and leak tests 4.1 General 4.1.1 Routine tests The pressure and leak tests specified in this clause shall, unless otherwise specified in the purchase order, be carried out by the manufacturer on each valve and shall, if stated in the purchase order, be conducted in the presence of the purchasers inspector. 4.1.2 Test liquid When hydrostatic testing is performed it shall be done using water at ambient temperature unless the use of some other liquid is agreed between purchaser and manufacturer. The water may contain a soluble oil or a rust inhibitor. 4.1.3 Test gauges Pressure gauges used in testing may be either indicating or recording instruments but shall be installed in such a manner that they represent the actual pressure in the component under test. They shall preferably have a range of approximately double but not less than 1.25 nor more than 4 times the actual test pressure. Test gauges shall be checked and recalibrated if necessary, at intervals not exceeding three months and a record of the results shall be kept. 4.1.4 Test certificates When specified by the purchaser the manufacturer shall issue a test certificate confirming that the valves have been tested in accordance with this standard and stating the pressure and the medium used in the test. BS 5793-4:1987 © BSI 08-19993 Table I Hydrostatic test pressure (bar or 100 kPa) Table II Duration of hydrostatic tests of shell 4.2 Shell test (hydrostatic) 4.2.1 General All control valve assemblies, with or without the actuator fitted, shall be subjected to a hydrostatic test of the shell as laid down in the relevant valve or flange standard or at the pressure shown in Table I, whichever is appropriate. The body ends shall be sealed in such a way that all cavities pressurized in service shall be simultaneously subjected to the test pressure for the duration stated in Table II. During this test the control valve shall be in the open position except that control valves with rotary action may be in the partially open position. Control valves incorporating backseats shall be held in a partially open position during testing. Precautions shall be taken to purge the valve of any residual air. The valve shall show no visible sign of leakage or porosity. The packing gland may be tightened if necessary to withstand the test pressure, but a small leak from the gland during the shell test is permissible. In order to minimize stem friction in service, the gland may be loosened, but shall remain tight enough to withstand the test pressure at the subsequent seat leakage test. By agreement with the purchaser, hydrostatic tests may be conducted on components. Conditions for retesting the complete assembly shall be agreed between manufacturer and purchaser. NOTETest equipment shall not subject the valve to externally applied stresses which may affect the results of the tests. If equipment such as volume lost devices is used for the test, the manufacturer shall be capable of demonstrating the equivalency of the system with the requirements of this standard. 4.2.2 Tightening torques Tightening torques applied to the bolts and nuts shall be as intended for use. 4.2.3 Removal of internal components Components such as bellows, diaphragms, backseats, stem packing, etc., which may be damaged by the hydrostatic test pressure may be removed. Ratings Materials Group 1Group 2Group 3Group 4Group 5Group 6 ShellSeatShellSeatShellSeatShellSeatShellSeatShellSeat PN 10151015101510151015101510 PN 16241624162416241624162416 PN 203021.52820302229185A-18.5122415 (Classes 150/125)5B-2114 PN 25382538253825382538253825 PN 40604060406040604060406040 PN 5077567253785775475A-41.527.55234 (Classes 300/250)5B-5234.5 PN 649664966496649664 PN 100154112.5 144105.5 15611414994 (Class 600) Group 1: Carbon steel.Group 5: Cast iron. Group 2: Carbon molybdenum steel, low carbon steel, nickel steel. Group 5A: Cast iron with minimum tensile strength of 145 MPa. Group 3: Low alloy and chrome molybdenum steels. Group 4: High alloy and stainless steels. Group 5B: Cast iron with minimum tensile strength of 214 MPa. Group 6: Copper alloy. Nominal size (mm) Test duration (s) Up to and including 5015 to 60 65 to 20060 to 120 250 and over180 to 420 NOTEThere is at present considerable variation in the minimum test duration specified in national and international standards for valves, pipes, and fittings. The values in Table II are ranges of times currently specified as minimum test duration. BS 5793-4:1987 4 © BSI 08-1999 4.2.4 Exclusions from hydrostatic test Welded-on nipples, reducers and/or expanders shall not be considered as