1、BRITISH STANDARD BS 6374-2: 1984 Lining of equipment with polymeric materials for the process industries Part 2: Specification for lining with non-sheet applied thermoplastics UDC 621.772.4:66.023.3:678.073BS6374-2:1984 This British Standard, having been prepared under the directionof the Pressure V
2、essels Standards Committee, was published under the authority ofthe Board of BSI and comesintoeffect on 31December1984 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference PVE/1 Draft for comment 81/78492 DC ISBN 0 580 141845 Committees responsible for th
3、is British Standard The preparation of this British Standard was entrusted by the Pressure Vessel Standards Committee (PVE/-) to Technical Committee PVE/1 upon which the following bodies were represented: Amalgamated Society of Boilermakers, Shipwrights, Blacksmiths and Structural Workers Associated
4、 Offices Technical Committee Association of Consulting Engineers British Chemical Engineering Contractors Association British Compressed Gases Association British Gas Corporation British Steel Industry Electricity Supply Industry in England and Wales Energy Industries Council Engineering Equipment a
5、nd Materials Users Association Health and Safety Executive Institution of Chemical Engineers Institution of Gas Engineers Institution of Mechanical Engineers Liquefied Petroleum Gas Industry Technical Association (UK) Process Plant Association Water-tube Boilermakers Association Welding Institute Co
6、opted member The following bodies were also represented in the drafting of the standard, through subcommittees and panels: British Rubber Manufacturers Association Institution of Corrosion Science and Technology Plastics and Rubber Institute Rubber and Plastics Research Association of Great Britain
7、Amendments issued since publication Amd. No. Date of issue CommentsBS6374-2:1984 BSI 08-1999 i Contents Page Committees responsible Inside front cover Foreword ii Section 1. General 1.1 Scope 1 1.2 Definitions 1 1.3 Exchange of information 2 1.4 Compliance 2 Section 2. Design, fabrication and surfac
8、e finish of equipment to be lined 2.1 General 3 2.2 Design of equipment to be lined 3 2.3 Fabrication of equipment to be lined 3 Section 3. Selection and quality of linings 3.1 Selection of lining 10 3.2 Quality of lining 10 3.3 Continuity of finished linings 10 Section 4. Method of lining 4.1 Surfa
9、ce preparation 11 4.2 Lining process 11 Section 5. Inspection and testing 5.1 Responsibility for inspection and testing 12 5.2 Inspection 12 Section 6. Methods of test 6.1 Continuity testing 13 Section 7. Rectification of faults in fully cured linings 7.1 General 14 Section 8. Storage, handling, tra
10、nsportation and installation 8.1 General 15 Appendix A Characteristics of lining materials specified in3.1 16 Appendix B Lining techniques 17 Appendix C Continuity testing 17 Figure 1 Pipework details 5 Figure 2 Weld profile details: butt welds 6 Figure 3 Weld profile details: external corners and e
11、dges 6 Figure 4 Weld profile details: internal corners and edges 7 Figure 5 Weld profile details: concave heads 8 Figure 6 Weld profile details: flanges 9 Publications referred to Inside back coverBS6374-2:1984 ii BSI 08-1999 Foreword This Part of BS 6374 has been prepared under the direction of the
12、 Pressure Vessels Standards Committee. It is one of five Parts of a new standard that will supersede Parts 1, 4, 5 and 6 of CP3003; the change in format arising from the fresh approach adopted to conform with developments in the associated lining technology. The Technical Committee would like to ack
13、nowledge the contributions made by the Rubber and Plastics Research Association of Great Britain which supplied the initial draft document, and the users and the manufacturers on whose submissions the document was based. The plastics linings referred to in this standard are used for a number of diff
14、erent duties, including protection against corrosive environments, prevention of contamination of products and surface finishes that do not foul easily or that can be cleaned easily. Specific linings are used for protection against abrasion or erosion. The linings are applied using fluidized bed dip
15、ping, powder spray, plastisol or liquid dipping, dispersion spray or solvent spray techniques. The thickness of linings based on these materials varies considerably with the particular plastic selected and ranges from504m to10mm. When the thickness of the lining is less than400 4m it is difficult to
16、 obtain linings which are pinhole free. Furthermore, even if linings as applied are free from imperfections, consideration has to be given to the possibility of damage in operation. Before selecting a lining and the thickness at which it will be applied, some knowledge is required of the likely corr
17、osion rate of the substrate and the mechanism of that corrosion. If the corrosion rate is low then the thickness of the lining is not a critical factor. If the corrosion rate is high and is due to simple solution of the metal, then it is not advisable to use thin linings because of the risk of sever
18、e corrosion through a pinhole. On the other hand, if a high corrosion rate is caused by an effect such as erosion/corrosion, then thin linings can be an effective barrier. It has been assumed in the drafting of this British Standard that the execution of its provisions is entrusted to appropriately
19、qualified and experienced people. 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
20、 of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 20, 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
21、 cover.BS6374-2:1984 BSI 08-1999 1 Section 1. General 1.1 Scope This Part of BS 6374 specifies requirements for the lining of equipment for the process industries using non-sheet applied thermoplastics. It includes requirements for the choice of lining and its application and also requirements for s
22、ubsequent inspection of the lining and the rectification of faults. NOTE 1The materials considered include thermoplastic powders, plastisols and dispersions. Although not thermoplastics, fusion-bonded epoxy resin powders are included in this category since the same application techniques are used. N
23、OTE 2The linings may be applied at the applicators works or on site. Requirements for design and fabrication of the equipment and the state of preparation necessary for the surfaces to be lined are specified in section2. Requirements for storage, handling, transportation and installation of the line
24、d equipment are specified in section8. This Part of BS 6374 does not apply to equipment manufactured in concrete. NOTE 3The titles of the publications referred to in this standard are listed on the inside back cover. 1.2 Definitions For the purposes of this Part of BS6374, the following definitions
25、apply. 1.2.1 plastic 1)(noun) a material that contains as an essential ingredient a high polymer and which at some stage in its processing into finished products can be shaped by flow NOTE 1Elastomeric materials, which are also shaped by flow, are not considered as plastics. NOTE 2In some countries,
26、 particularly in the United Kingdom, the official position now is that it is a permitted option to use the term “plastics” as the singular form as well as the plural form. 1.2.2 resin 1) a solid, semisolid, or pseudosolid organic material that has an indefinite and often high relative molecular mass
27、, exhibits a tendency to flow when subjected to stress, usually has a softening or melting range and, usually fractures conchoidally. In a broad sense, the term is used to designate polymer that is a basic material for plastics 1.2.3 thermoset 1)(noun) a plastic which, when cured by heat or other me
28、ans, changes into a substantially infusible and insoluble product NOTEThis term includes both thermosetting plastics and thermoset plastics. 1.2.4 purchaser 2) the organization or individual who buys the lined equipment for its own use or as an agent for the owner 1.2.5 fabricator 2) the organizatio
29、n or individual responsible for the fabrication of the equipment to be lined 1.2.6 applicator 2) the organization or individual responsible for the application of the lining 1.2.7 inspection authority 2) the body or association appointed by the purchaser (or owner) to check that the design, fabricat
30、ion, and lining comply with this standard 1.2.8 lining a non-sheet applied thermoplastic or fusion-bonded epoxy coating which requires, where necessary, the equipment to be preheated and/or post-application stoving NOTEAlthough in common usage the terms “lining” and “coating” are interchangeable, in
31、 this document “lining” will be used. 1.2.9 cure the chemical reaction resulting in the final polymerized product 1.2.10 pinhole a small defect in the lining that would permit corrosion of the substrate under the conditions for which the lining is designed NOTEThe word “pinhole” is synonymous with “
32、holiday” and “pore”. 1) These terms have been extracted from BS 1755-1. 2) Where the words “purchaser”, “fabricator”, “applicator” and “inspection authority” occur in the text, they are intended also to include representatives of the purchaser, fabricator, applicator and inspection authority.BS6374-
33、2:1984 2 BSI 08-1999 1.2.11 blister a gas or liquid filled cavity within the lining material or between the lining and substrate 1.3 Exchange of information Early consultation shall be arranged between all parties concerned with the application of this standard, to establish the following informatio
34、n which shall be fully documented. Both the definitive requirements specified in this standard and the documented items shall be satisfied before a claim of compliance with the standard can be made and verified. a) Design and fabrication details of the equipment to be lined and provision of drawings
35、 (see2.2 and2.3). b) Details of gasket materials (see2.2.9 and2.2.10). c) Details of the contents of the vessels or equipment, including trace materials see3.1.1 a). d) The design temperature see3.1.1 b). e) The design pressure see3.1.1 c). f) The details of any solids to be handled see3.1.1 e). g)
36、The methods of heating and/or cooling see3.1.1 b). h) Cleaning methods, for example, water washing, solvent washing, boiling out or steaming see3.1.1 a). i) Where the lining work will be done. j) Site conditions that may affect the work, for example availability of services. k) Any special requireme
37、nts for materials used in blast cleaning (see4.1.3). l) The type of material to be used for lining (see3.1.1). m) The minimum thickness of the lining and where applicable the maximum thickness (see3.2.2). n) The provision of test pieces (see3.2.1 and5.2.3). o) The maximum number of pinholes per squa
38、re metre of surface if they are permitted (see3.3 and5.2.5). p) The maximum and minimum allowable temperature that is required for the correct application of the lining (see4.2). q) The minimum temperature required during the curing of the lining (see4.2). r) Inspection techniques/procedures to be e
39、mployed, acceptance levels and stages of inspection (see5.1, 5.2 and6.1). s) Use of different materials for repair (see7.1). t) Handling, transport, storage and installation procedure (see3.1.1g) and8.1.1 to8.1.7). 1.4 Compliance 1.4.1 Fabricator The fabricator shall comply with the following: a) se
40、ction 2 see1.3 a); b) 5.1 a) andb); c) section 8 as agreed in1.3 t). 1.4.2 Applicator The applicator shall comply with the following: a) section 3 (but see3.2.1); b) section 4; c) 5.1 c),d),e) andf); d) section 6; e) section 7; f) section 8 as agreed in1.3 t).BS6374-2:1984 BSI 08-1999 3 Section 2. D
41、esign, fabrication and surface finish of equipment to be lined 2.1 General The basic design, fabrication and testing for mechanical reliability of the equipment to be lined shall be carried out to appropriate British Standards and shall comply with2.2 and2.3 before the lining operation commences. 2.
42、2 Design of equipment to be lined 2.2.1 Equipment to be lined shall be sufficiently rigid that there is no possibility of deformation which could result in damage to the lining during transportation, installation and operation. When stiffeners are required, they shall normally be applied to the unli
43、ned side of the equipment. 2.2.2 The arrangements for the lifting of equipment shall be determined at the design stage. 2.2.3 The design of all equipment shall allow for access during the preparation of the surface and application of the lining and for venting of fumes evolved during the operation.
44、In completely enclosed vessels there shall be at least one manhole that after lining complies with BS470 and one additional branch of not less than75mm bore to permit adequate circulation of air. NOTEIt is recommended that, where practicable, the minimum diameter of a manhole should be600mm. 2.2.4 R
45、iveted constructions shall not be used. 2.2.5 Bolted joints shall be permitted only if they can be dismantled for lining. 2.2.6 Surfaces to be lined shall be of a smooth contour. 2.2.7 Discontinuities, crevices and sharp projections shall be avoided. 2.2.8 Fittings that have to be installed after th
46、e completion of the lining process shall be designed to be lined or fabricated from materials that will not be affected by the process conditions. 2.2.9 Normally all connections to lined parts of equipment shall be flanged. If for any reason screwed connections are required, then these parts shall b
47、e fabricated in corrosion-resistant materials. 2.2.10 All nozzles and outlets shall be as short as possible, straight and flanged. Flange faces shall have a plain surface to allow the lining to continue over the face. 2.2.11 Heating coils, immersion heaters and sparger pipes shall be installed after
48、 the completion of the lining process and shall be located so that no part is closer than100mm from a lined surface, in the case of nozzles through which heating coils, etc.enter equipment, a smaller clearance is permitted provided that the temperature of the pipe through the nozzle does not exceed8
49、0 C. In no case shall this clearance be less than25mm. Fluid introduced through sparger pipes or dip pipes shall not impinge directly on to the lining. External heating of equipment shall not be permitted without full consultation with the applicator of the lining. 2.2.12 The design of pipework shall be such as to allow ready access to welds and bends for inspection and surface preparation. NOTESystems made up from straight lengths with separate bends and tees meet this requirement (seeFigure 1). Where pipes incorporating branches and bends are to
