BS 3505:1986 download.Specification for Unpiasticized polyvinyl chloride (PVC-U) pressure pipes for cold potable water.
1 Scope
BS 3505 specifies requirements for unpiasticized polyvinyl chloride (PVC-U) pipes up to and including nominal size 24, for conveying cold potable water at pressures up to and including 9, 12 or 15 bar’ at 20 °C, depending on the size.
Methods of test, associated guidance and information on quality control testing are given in appendices.
NOTE The titles of the publications referred to in this standard are listed on the inside back cover.
2 Material
2.1 Base material
The material from which the pipe is produced shall be polyvinyl chloride with additives as necessary for the manufacture of pipe in accordance with this standard and to satisfy colour requirements, if applicable (see foreword and 6.1.2).
2.2 Reworked material
If reworked material is added or used, it shall be clean and in accordance with 2.1; it shall be derived from pipe produced in accordance with this standard, reground under the supervision of the same manufacturer and used only in the production of pipe sizes up to and including nominal size 6.
3 Pressure classification of pipes
Pipes are classified by maximum sustained working pressure, as follows:
a) 9 bar (class C);
b) 12 bar (class D);
c) 15 bar (class E).
NOTE The working pressures given above are the calculated maximum sustained working pressures for the conveyance of cold water at a temperature of 20 °C. For use at higher temperatures or under conditions of pulsating pressures, reference should be made to CP 312-2.
4 Dimensions and tolerances
4.1 Nominal size
The nominal size of the pipe shall be one of the sizes given in Table 1.
4.2 Outside diameter
When determined in accordance with BS 2782:
Method 1IO1A, the outside diameter of the pipe shall comply with the limits specified in Table I for the relevant nominal size of the pipe.
4.3 Wall thickness
When determined in accordance with
BS 2782: Method 1 l0lA, the wall thickness of the pipe shall comply with the limits specified in Table 1 appropriate to the nominal size and class of pipe. The average wall thickness of the pipe shall be determined by taking the arithmetic mean of at least the following number of measurements of wall thickness around the pipe, including both the minimum and maximum values:
a) up to and including 6 mm wall thickness: four measurements;
b) greater than 6 mm wall thickness: six measurements.
4.4 Tolerance on length
The ends of pipes shall be cut cleanly and squarely. If the length of a pipe is specified, the effective length shall be not less than that specified, when determined at 23 ± 2 °C.
NOTE The preferred effective lengths of pipe are 6 m or 9 m. For plainended pipes, the effective length corresponds to the overall length. For pipes with an integrally formed ring seal joint in accordance with BS 4346-2, the effective length does not include the length required for the joint.
5 Performance requirements
5.1 General
The requirements given in 5.2 and 5.3 shall be met, subject to 5.4, which shall apply whenever a change in process technique or introduction of a new or modified compound has occurred.
The relevant tests shall be applied to pipe taken from a production run from which the product has complied with all the other requirements of BS 3505.
5.2 Hydrostatic properties
NOTE Attention is drawn to advice given in appendix E concerning samples of pipes of different design stress categories. formulations, pressure classifications and sizes.
5.2.1 Long-term hydrostatic strength at 20 °C. When test pieces in accordance with 5.2.2 are tested at 20± 1 °C in accordance with BS 4728, and the results are analysed in accordance with appendix A, the extrapolated values for circumferential wall stress for the periods of time given in Table 2 shall comply with the limits specified in Table 2 according to the applicable design stress category.
NOTE 2 Pending the determination of suitable means of characterizing the toxicity of leachates from materials in contact with potable water, materials approved by the Department of the Environment Committee on Chemicals and Materials of Construction for use in Public Water Supply and Swimming Pools are considered free from toxic hazard for the purposes of compliance with this subclause. A list of approved chemicals and materials is available from the Technical Secretary of that Committee at the Department. of the Environment. Water Division, Romney House, 43 Marsham Street, London SW1P 3PY, NOTE 3 Products manufactured for installation and use in the United Kingdom which are verified and listed under the UK Water Fittings Byelaws Scheme administered by the Water Research Centre (address as in note 1) are deemed to satisf’ the requirements detailed in this subclausc.
5.4 Extension to nominal size, formulation or process range
For the extension of a manufacturer’s range of sizes beyond that already tested in accordance with 5.1 to 5.3 or for a change in either the material formulation or pipe manufacturing process, the manufacturer can claim compliance for the modified range, provided that the additional pipes in the range satisfy the following requirements.
a) All the requirements of this standard except 5.2.1 shall be met.
b) At failure times up to 2 500 h, the requirements of 5.2.1 in respect of the minimum circumferential wall stress for 50 years shall be met.
c) Sufficient test pieces shall be under test, at appropriate stress levels, to enable a full regression analysis to be carried out in accordance with 5.2.1.
d) The requirements of 5.2.1 shall be met subsequently by the test pieces under test in accordance with (c).
6 Physical properties
6.1 Appearance
6.1.1 Superficial appearance. When viewed without magnification, the internal and external surfaces of the pipe shall be free from defects and the internal surface shall appear to be clean.
NOTE The ends of the pipes may be plugged or covered to maintain their condition and exclude contamination.
6.1.2 Colour. The following shall apply.
a) In the case of pipes of nominal size 2 or smaller intended for buried utilities for cold potable water, the colour of the pipe shall be blue within the range 18 E 51 and 18 F4 53 of BS 4901.
b) In the case of pipes of nominal size 2 or smaller, if grey, the colour shall be darker than colour 00 A 09 of BS 4800.
6.5 Impact resistance at 20 °C
When tested in accordance with appendix B, the pipe shall have a true impact rate (TIR) below 10 % at a confidence level of 90 %.
6.6 Fracture toughness
This requirement shall only apply to pipes of nominal size 3 or greater, which, when tested in accordance with appendix C, shall withstand for not less than 15 mm without breaking or cracking at the notch the test force corresponding to a true fracture toughness, K1 (see appendix D), of not less than 3.25 MN m3”2 for pipes of wall thickness e less than 6 mm or not less than 3.75 MN in’112 for pipes of wall thickness e greater than or equal to 6 mm.
7 Marking
7.1 All pipes shall be indelibly marked in accordance with 72. at intervals not exceeding 1 rn with the following information:
a) the manufacturer’s identification, as a clear
text or logo;
b) the number and date of this British Standard
i.e. BS 3505:19862);
c) the letters PVC-U”;
d) the pressure classification, in bars, in
accordance with clause 3. e.g. 12 barn;
e) the nominal size in accordance with Table 1; a batch identification.
7.2 The marking shall be imprinted longitudinally in one of the following colours, as applicable:
a) for 9 bar (class C) pipe: black4 or dark blue;
b) for 12 bar (class D) pipe: green;
c) for 15 bar (class E) pipe: brown.