1、THE ENGINEERING EQUIPMENT AND MATERIALS USERS ASSOCIATION CODE OF PRACTICE FOR THE IDENTIFICATION AND CHECKING OF MATERIALS OF CONSTRUCTION IN PRESSURE SYSTEMS IN PROCESS PLANTS PUBLICATION No 149 : 1997 THE ENGINEERING EQUIPMENT AND MATERIALS USERS ASSOCIATION CODE OF PRACTICE FOR THE IDENTIFICATIO
2、N AND CHECKING OF MATERIALS OF CONSTRUCTION IN PRESSURE SYSTEMS IN PROCESS PLANTS PUBLICATION No 149 : 1997 Copyright 1997 The Engineering Equipment and Materials Users Association ISBN O 85931 081 7 45 Beech Street LONDON EC2Y 8AD EEMUA Telephone: 0171-628 7878 Fax: 0171-628 7862 STD*EEMUA PUB NO 1
3、47-ENGL 1777 = 57bb734 0000004 22T M THE ENGINEERING EQUIPMENT AND MATERIALS USERS ASSOCIATION The Engineering Equipment and Materials Users Association-EEMUA-was formed in 1983 by the Amalgamation of the Oil Companies Materials Association (OCMA) and the Engineering Equipment Users Association (EEU
4、A). It is an organisation of substantial purchasers and users of engineering products, whose members include leading national and multi-national companies in the petroleum, gas; chemical and energy industries. A list of Full and Associate Members (the latter being limited to membership of three tech
5、nical committees) is given below. EEMUA is concerned with the design, installation, operation and maintenance of the engineering plant used by members in pursuing their business activities. The Association aims to reduce members costs by providing the opportunity for them to share resources and expe
6、rtise in order to keep abreast of technological developments and improve the effectiveness and efficiency of their engineering activities. EEMUA supports the British Standards Institution, works with other institutions, associations, government departments, regulatory authorities and the Confederati
7、on of British Industry, and is also actively involved with other standards-making bodies, both national and international, such as the American Petroleum Institute. Work, which is carried out in-house by members alone or with the help of other organisations, may lead to the production of Association
8、 publications. These are prepared primarily for members use, but are usually offered for sale and thus for more general use. Such publications may also be submitted, normally through the British Standards Institution, as bases for appropriate national, European or international standards. A list of
9、current EEMUA Publications which may be purchased From the Association is given at the end of this document. Full Members Associate Members Associated Octel BG BP Amoco Caltex Petroleum Conoco Dow Corning Eastern Generation Esso/ExxonMob i I Eutech Foster Wheeler Energy Lindsey Oil Refinery National
10、 Power PowerGen Shell AstraZeneca BASF D where such guarantees are considered necessary, more rigorous measures may be needed. The original, 1986, issue of this Code of Practice was intended to be applied to new equipment. This 1997 edition has been comprehensively revised by the EEMUA Inspection th
11、e pipework with its protective devices to which a transportable gas container is, or is intended to be, connected; or a pipeline and its protective devices. 5 Previous page is blank STD=EEMUA PUB NO LLiS-ENGL 1797 57bb73Li OODOOLO 523 M 4. IDENTIFICATION AND CLASSIFICATION OF PIPEWORK REQUIRING TO B
12、E SUBJECTED TO MATERIAL VERIFICATION (SMV) 4.1 Identification 4.1.1 Pipework should always be subjected to material verification when the conditions under which it operates are such that a failure attributable to the inclusion of incorrect materials may occur, and when the consequences of such failu
13、re are unacceptable in regard to the likely hazards to personnel or plant and production losses. A pragmatic decision may be taken to check all equipment in the pressure system which contains alloy materials. There are, however, a number of sophisticated risk based inspection (RBI) procedures which
14、may be used to calculate a risk factor based on the likelihood and consequences of failure - e.g. those to be included in API 580 (see Appendix II). The extent to which a pressure system is to be subjected to material verification may, therefore, range from those parts of the pipework containing all
15、oy materials and liable to unacceptable failure, to an entire pressure system allotted a given risk factor. 4.1.2 The conditions to be assessed include pressure, temperature, nature of fluid (toxic and/or flammable) and location of the pipework or component thereof in relation to plant, buildings or
16、 personnel. From the above it follows that due to location, or changes in other conditions, parts of a pipework system may have differing degrees of risk associated with a possible loss of containment. It may not therefore be necessary for an entire system to be subjected to material verification. 4
17、.2 Classification 4.2.1 Systems requiring material verification, either in whole or in part, in accordance with the foregoing criteria should be classified SMV and this should be stated in the appropriate documents. 4.2.2 For new projects, all pipework (and other equipment if considered necessary) s
18、hould be considered by the Design Authority and classified SMV, in whole or in part, where appropriate. 4.2.3 For existing plants, thorough and systematic consideration should be given to classifying all alloy-containing pipework (and other equipment if considered necessary) as SMV. As an immediate
19、precaution, whenever replacement pipework is required or pipework modifications are to be carried out and the original drawings do not clearly and unambiguously indicate the classification of the relevant pipework, then the Operations Authority should, in conjunction with the Design Authority, ident
20、ify and classifj the pipework as required by this section. 7 Previous page is blank 1 STD=EEMUA PUB NO LVS-ENGL 1997 57bb734 0000011 4bT 5. IDENTIFICATION OF PIPEWORK (OR OTHER EQUIPMENT) OTHER THAN SMV No special action is required for non-SMV systems or components. This is not to be taken as meani
21、ng that it is of no concern whether or not the correct material is used for those systems. All the usual checks for correct specification, identification, scrutiny of test certificates etc., should apply. 9 Previous page is blank STD=EEMUA PUB NO LLiq-ENGL 1997 57bb73q OUOOL2 3Tb 6. MATERIALSUPPLY T
22、he supply chain from raw material to installed component involves a number of processes and organisations - e.g. material and component manufacture, material stockist, site receipt and storage - where errors leading to incorrect identification can arise. It is in the longer term interest of all part
23、ies that procedures and controls at all stages of the chain should be adequate to prevent mistakes (e.g. through the use of techniques such as those in the applicable standards in the BS EN IS0 9ooo-9004 series of quality standards - see Appendix II). Visual identification of components by means of
24、colour coding is an essential part of the total quality control system; one widely used standard is BS 5383. It is the duty of the manufacturer or stockist to ensure that materials are correctly marked. However colour coding, character printing and hard stamping are only aids to identification. The
25、purchaser should require the supplier to ensure that adequate measures are taken to satisfy himself, and the purchaser, beyond reasonable doubt that the materials which he supplies are those which were ordered and that they are correctly marked. In the case of SMV systems it will be necessary to car
26、ry out positive material identification (PMI) checks using one of the methods outlined in Appendix I as mutually agreed with the Inspection Authority; elements to be verified and method of checking are to be mutually agreed in advance, Material subjected to conformance checks should, if found to con
27、form, be so marked with an appropriate symbol. The supplier or stockist should supply a certificate of conformity traceable against material supplied with each consignment detailing: (a) (b) (c) (d) the specification with which the goods purport to conform the check tests applied by him a facsimile
28、of the symbol indicating that appropriate check tests have been applied and the material has been found to conform the marks identifying the consignment. Such certificates should be additional to any certification required by the specification relating to the components in question. 11 Previous page
29、 is blank 7. SHOP AND SITE FABRICATION The possibility of accidental use of the wrong material increases as the number of separate material specifications for pipework (or other equipment) increases. The potential for error can be reduced by restricting the number of different specifications and by
30、segregating specifications for off- or on-site fabrication in different workshops, by different contractors etc., as well as by rigorous control of materials as stated in this Code. 13 Previous page is blank “ STDDEEMUA PUB NO 149-ENGL L997 57bb73i 0000014 174 9 8. SITE MATERIAL CHECKS AND RECORDS 8
31、.1 Pre-service Site Material Checks It is recommended that all parts of SMV systems be checked either during or after erection and before going into service to ensure that all materials conform to those specified. Every component which is built into the system should be subjected to PMI, including w
32、eld metal. For some services, it will also be necessary to check flange bolting and gaskets. Checking should be carried out using an approved instrument or method defined in Appendix I, or in such other way as may be agreed. In some cases it is very difficult to positively identifj special grades of
33、 material by means of the nondestructive testing methods outlined in Appendix I, e.g. impact tested carbon steel or low carbon grades of austenitic steel. Metallurgical advice should be sought on the best technique to use and the accuracy which may be expected from it. In some cases reliance may hav
34、e to be placed on specially detailed documentation, and marking of materials adequately tested at an earlier stage. It should also be noted that, at the present time, the materials checking methods available can only check the surface composition of welds which may not be representative of earlier p
35、asses. When it is essential that the whole of the weld metal be verified, then checks during the welding cycle should be made on deposits of the actual electrodes or filler wire used. The checks referred to above apply to both shop and site fabricated pipework items at the time they are erected to o
36、ccupy their final place in the pipework system. In some cases checking may be relaxed for clearly marked, identified and documented items which have been prefabricated off site under similar close control. Such relaxation should be agreed by the responsible Authorities. In no case should final check
37、ing be totally eliminated; a recommended 10% minimum of all items should be checked after erection, even when it is believed that rigorous offsite control was applied. 8.2 Retrospective Site Material Checks Existing in-service equipment that has been retrospectively classified SMV under paragraph 4.
38、2.3 should be subjected to material verification by PMI. 8.3 Records Records of all materials checked in accordance with this Code, and of any heat treatment, both on- and off-site, should be retained in the plant history files and be traceable to the installed pipework and/or other equipment. 15 Pr
39、evious page is blank APPENDIX I: METHODS USED FOR CHECKING MATERIALS The method adopted for the positive identification of materials will depend on many factors, e.g. the variety of different materials which have to be scanned, their key (chemical) elements for positive identification, the analytica
40、l capability of the method or instrument used, environmental factors (temperature, access, area classification), and the importance of accuracy. Some of the methods available, with their advantages and disadvantages, are outlined below. New and improved instruments using these principles are being c
41、ontinually introduced and the balance of advantages and disadvantages may differ from those described. This, coupled with the implications of the specific requirements in each particular case, make it advisable to consult materials specialists on the appropriate method to use. 1. Spectrography An el
42、ectric arc is struck between the instrument and the material being tested, and is analysed spectrographically. (a) Portable equipment. Advantages: - small and light - - - fully portable with battery pack power supply materiais accurately identified if equipment used correctly safe for operator (36 v
43、olts at electrodes). Disadvantages: - - specially trained and experienced operator required under site conditions, difficult to differentiate between various grades of low alloy steel, e.g. 1%XCr %Mo from 2%Cr 1%Mo and other low alloy steels with a Cr content 1 % carbon content determination is not
44、possible with an air arc possibility of electrode contamination by the element from the previous sample; periodic grinding of electrodes required shallow arc strike damage to sample possible body of instrument becomes hot after protracted use open arc, hence cannot be used in hazardous areas - - c -
45、 - - operator fatigue. (b) Semi-portable equipment. Larger semi-portable, fully automatic analysers are also available, some utilising appropriate gas atmospheres for the arc thereby allowing carbon content determination. These analysers require less operator skill; also fatigue is less of a problem
46、. 17 Previous page is blank 2. X-ray Fluorescence Small radioactive sources are used to excite surface layer atoms of the sample causing them to fluoresce, emitting secondary radiation. A detector and associated electronics are used to detect and analyse the emitted radiation to determine the chemic
47、al composition of the sample material. Generally only two excitation isotopes (Fe-55 and Cd-109) are required. Advantages: - can be calibrated for quantitative results - - suitable for sorting of austenitic stainless steels comparison with library alloy analysis possible when used in grade or sort m
48、ode possible to use less experienced operators. - Disadvantages: - for fully quantitative measurement calibration curves or standard samples may be needed length of setting up procedure may limit application where only a small number of specimens are to be tested surface has to be free of scale and
49、oil - - - possible radiation hazard high costs associated with source replacement and recalibration. 3. Chemical Analysis (a) Physical removal of a piece of metal for laboratory analysis by wet chemical or spectrographic means. Advantages: - very accurate results possible. Disadvantages: - - - danger of sample contamination (from cutting tool or otherwise) potential for sample mix up could weaken component from which sample is taken. (b) In-situ spot analysis by depositing reagent on specimen. Advantages: - cheap - quick - simple to apply. 18 Disadvantages: - only
