BS 5955-8-2001 Plastics pipework (thermoplastics materials) Specification for the installation of thermoplastic pipes and associated fittings for use in domestic hot and cold servi.pdf

1、BRITISH STANDARD BS 5955-8:2001 Plastics pipework (thermoplastic materials) Part 8: Specification for the installation of thermoplastic pipes and associated fittings for use in domestic hot and cold services and heating systems in buildings ICS 83.140.30; 91.140.10; 91.140.60 NO COPYING WITHOUT BSI

2、PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS 5955-8:2001 This British Standard, having been prepared under the direction of the Materials and Chemicals Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 22 October 2001 BSI 2

3、2 October 2001 First published May 1990 Second edition October 2001 The following BSI references relate to the work on this British Standard: Committee reference PRI/88 Draft for comment 00/12232 DC ISBN 0 580 38561 2 Committees responsible for this British Standard The preparation of this British S

4、tandard was entrusted by Technical Committee, PRI/88, Plastic piping systems, to Subcommittee PRI/88/2, Thermoplastic piping systems and components for pressure applications, upon which the following bodies were represented: British Adhesives and Sealants Association British Plastics Federation Brit

5、ish Plumbing Fittings Manufacturers Association Chartered Institute of Water and Environment Health and Safety Executive Institute of Materials Institution of Civil Engineers Institution of Gas Engineers National Association of Plumbing and Heating Standards Association of Australia Water UK Amendme

6、nts issued since publication Amd. No. Date CommentsBS 5955-8:2001 BSI 22 October 2001 i Contents Page Committees responsible Inside front cover Foreword ii 1S c o p e 1 2 Normative references 1 3T e r m s a n d d e f i n i t i o n s 1 4 Classification 2 5 Design considerations 2 6 Installation work

7、on site 3 7 Commissioning 6 Annex A (informative) Guidance on storage, handling and transport 7 Annex B (informative) Guidance on jointing techniques 7 Bibliography 9 Table 1 Recommended spacing of support centres for PB and PE-X pipes 4BS 5955-8:2001 ii BSI 22 October 2001 Foreword This British Sta

8、ndard has been prepared under the direction of the Plastics Standards Committee. Its preparation was entrusted by Technical Committee PRI/88, Plastics piping systems and components, to Subcommittee PRI/88/2, Plastics piping systems and components for pressure applications. It supersedes the 1990 edi

9、tion, which is now withdrawn. It specifies methods and gives requirements for the installation of polybutylene (PB) and crosslinked polyethylene (PE-X) pipes and associated fittings compatible with the scope of BS 7291:2001. It is intended for the use of engineers, architects, surveyors, contractors

10、, installers and inspection authorities for purposes of use of hot and cold water, including heating systems in buildings. To further assist end-users, requirements have also been given for jointing systems which may be used with these components, together with recommended methods of storage, handli

11、ng and transport. NOTE In the preparation of this standard, the opportunity has been taken to present it in the form of a practice specification in accordance with the guidance given in PD 6612:1997. This format allows the requirements of the specification to be supported by recommendations. To comp

12、ly with this specification, the user has to comply with all its requirements. The user may depart from recommendations, but this would be on his own responsibility and he would be expected to have good reasons for doing so. Attention is drawn to BS 1710 for a specification on identification and mark

13、ing of service pipework to discriminate between different applications and/or pipework for other purposes. This is not intended to imply that the requirements given in BS 1710 for the marking of pipework are either necessary or desirable for installations in situations used only for domestic purpose

14、s. Annex A and Annex B are informative. 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. I

15、nstallations covered by this part of BS 5955 fall within the scope of the Water Supply (Water Fittings) Regulations 1 and/or relevant byelaws, and persons using this standard should therefore be conversant with the applicable Water Regulations. Guidance on water regulations matters can be obtained f

16、rom local water undertakers or from the Water Regulations Advisory Scheme. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 9 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.BS

17、5955-8:2001 BSI 22 October 2001 1 1 Scope This part of this British Standard specifies the practices to be followed in the application and installation of thermoplastics pipes and associated fittings which fall within the scope of BS 7291:2001 and are used for the distribution of hot and cold water,

18、 including drinking water, and heating systems within buildings. Guidance is also given on acceptable methods of jointing polybutylene (PB) and crosslinked polyethylene (PE-X) pipes and associated fittings, together with recommendations on their storage, handling and transportation. Whilst it is rec

19、ognized that in the majority of installations there will be combination of plastics and metallic components, guidance is only given for those parts of the installation where thermoplastics pipes and/or associated fittings are utilized, except where a transition occurs between plastics and metallic c

20、omponents. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of this British Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. For unda

21、ted references, the latest edition of the publication referred to applies. BS 5449, Specification for forced circulation hot water central heating systems for domestic premises. BS 5970, Code of practice for thermal insulation of pipework and equipment (in the temperature range 100 C to +870 C). BS

22、6920-1:2000, Suitability of non-metallic products for use in contact with water intended for human consumption with regard to their effect on the quality of the water Part 1: Specification. BS 7291-1:2001, Thermoplastics pipes and associated fittings for hot and cold water for domestic purposes and

23、heating installations in buildings Part 1: General requirements. BS 7291-2, Thermoplastics pipes and associated fittings for hot and cold water for domestic purposes and heating installations in buildings Part 2: Specification for polybutylene (PB) pipes and associated fittings. BS 7291-3, Thermopla

24、stics pipes and associated fittings for hot and cold water for domestic purposes and heating installations in buildings Part 3: Specification for crosslinked polyethylene (PE-X) pipes and associated fittings. BS 7671, Requirements for electrical installations IEE Wiring Regulations. BS EN 681-1, Ela

25、stomeric seals Material requirements for pipe joint seals used in water and drainage application Part 1: Vulcanized rubber. BS EN 1254-2, Copper and copper alloys Plumbing fittings Part 2: Fittings with compression ends for use with copper tubes. BS EN 1254-3, Copper and copper alloys Plumbing fitti

26、ngs Part 3: Fittings with compression ends for use with plastics pipes. 3 Terms and definitions For the purposes of this part of BS 5955, the terms and definitions given in BS 7291-1:2001 and the following apply. 3.1 boiler appliance designed for heating water either for heating systems or hot water

27、 supply 3.2 circulator appliance designed for the supply of hot water in conjunction with a separate storage vessel, operated by gravity circulation 3.3 component part of an installation which can be either plastics or metallicBS 5955-8:2001 2 BSI 22 October 2001 3.4 installation complete assembly f

28、or the provision of hot and cold water and/or heating systems 3.5 pipework system parts of an installation which comprise thermoplastics pipes and associated fittings 4 Classification The pipework system shall be classified in accordance with the classifications for thermoplastics pipes and associat

29、ed fittings specified in BS 7291-1:2001, i.e. class W, H or S. 5 Design considerations 5.1 Service conditions The installed pipework system shall be capable of operation at the service conditions appropriate to the applications in accordance with BS 7291-1:2001, Table 2. 5.2 Materials All components

30、 used shall be suitable for the maximum system temperatures and pressures as specified in BS 7291-1:2001 for their intended application. Components of PB and PE-X shall conform to the requirements appropriate to their class as given in the relevant British Standard(s), i.e.: 5.3 Water quality 5.3.1

31、Effect of materials on the quality of water When used under the conditions for which they are designated, non-metallic products in contact with or likely to come into contact with water fit for human consumption shall conform to the requirements of BS 6920-1:2000. NOTE 1 Non-metallic products for in

32、stallation and use in the United Kingdom which are verified and listed under the UK Water Regulations Advisory Scheme are deemed to satisfy the requirements of this sub-clause. Details of the Scheme are available from WRc Evaluation and Testing Centre Ltd, Fern Close, Pen-y-Fan Industrial Estate, Oa

33、kdale, Gwent. NP1 4EH. NOTE 2 A list of approved chemicals and materials and details of the approvals scheme is available from the Secretary of the Committee at the Department of the Environment, Drinking Water Directorate, Floor 2/E5, Ashdown House, 123 Victoria Street, London. SW1E 6DE. NOTE 3 The

34、re is no corresponding British Standard and associated test methods generally applicable to metallic products, i.e. complete fittings or parts of fittings which may come into contact with potable water. Attention is drawn to the UK Water Regulations Advisory Scheme (see note 1) and to the relevant r

35、equirements for fittings conforming to BS EN 1254-2 and/or BS EN 1254-3 or equivalent. 5.3.2 Effect of materials on heating systems If the material from which the plastics components are constructed can affect the reactivity of recirculated water, or vice versa, this shall be taken into account when

36、 determining the type and variety of materials used in the design of the system and the need for and selection of system additives (see 5.3.3). COMMENTARY AND RECOMMENDATIONS ON 5.3.2. Recirculated water can be affected by leaching of constituents from the components and/or by permeation of gas or v

37、apour through the walls of the components. The effects can be deleterious to other systems components, but may be reduced by use of appropriate additives. If the system environment is other than air and the system contents other than water, it could be necessary to consider the possibility of reacti

38、ons and effects additional to those catered for in BS 7291-1:2001 and the applicable material related part(s) of that standard. PB BS 7291-2 PE-X BS 7291-3BS 5955-8:2001 BSI 22 October 2001 3 5.3.3 System additives Where a corrosion inhibitor or other water treatment is recommended for a heating sys

39、tem by the plastic components manufacturer, this shall be applied in accordance with the manufacturers instructions. NOTE Attention is drawn to 5.3.1. COMMENTARY AND RECOMMENDATIONS ON 5.3.3. The use of a system additive may be required to prevent deterioration of steel components (e.g. radiators),

40、and to keep the water condition reasonable for circulation efficiency. The correct level of additive concentration, and method of checking concentration level and system water condition, will normally be advised by the corrosion inhibitor manufacturer. Corrosion inhibitor additives should only be us

41、ed in thermoplastic piping systems where the inhibitor manufacturer verifies that the product will not adversely affect the long term performance of the piping system and where such additives are produced under a BS EN ISO 9000 Quality Management and Quality Assurance Standard. Where system additive

42、s are used, these should be applied in accordance with BS 7593. 5.4 Pipe sizing The sizes of pipes and fittings used in an installation shall be such as to provide an adequate flow and/or delivery of water for the application of the installation. Water velocities for heating systems shall conform to

43、 BS 5449. COMMENTARY AND RECOMMENDATIONS ON 5.4. It is customary when sizing metal piping for domestic hot water systems to use frictional loss data related to cold water temperature. The density of cold water is more than hot water effectively providing a safety factor for some scale build-up. Plas

44、tic components have smooth, glossy internal surfaces, which discourage the accumulation of limescale in hard water areas and pitting and corrosion in soft water areas. The bore diameter will therefore be maintained almost indefinitely. For the purpose of calculating design flow rates, refer to BS 54

45、49. Head loss for piping can be calculated by using the pipe manufacturers published data, or by using suitable graphs, which allow for the correct internal pipe diameter to be applied. As thermoplastic piping has excellent noise attenuation and is not susceptible to corrosion, hot and cold water fl

46、ow velocities up to 3 m/s are acceptable for the distribution pipework and velocities of up to 5 m/s are acceptable for short final appliance connections. 6 Installation work on site 6.1 Pipework 6.1.1 Positioning The positioning and supporting of pipes shall allow for free movement, for expansion a

47、nd be such as to avoid airlocks. Pipes running through brickwork, masonry and solid floors shall be sleeved to allow movement of the pipe without damage to the building fabric or pipe. The overall length of the sleeve shall be such that it projects at least 2 mm beyond the finished thickness of the

48、wall or partition. COMMENTARY AND RECOMMENDATIONS ON 6.1.1. Holes should be used through joists in preference to notches to avoid a reduction in the structural strength of the joists and inadvertent damage to the pipework. In general, with the exception of underfloor heating systems, pipework should

49、 not be embedded in concrete or masonry unless it is installed without joints as part of a heating system, or run within a conduit, which allows for future pipe replacement. Where it is required to run jointed pipework in concrete or masonry, it should be provided with properly designed ducts or chases fitted with removable covers or covered by decorative material which allows reasonable ease of access in accordance with the Water Regulations and/or byelaws. To minimize the risk of accidental damage to pipework and, with the exception of pipework r