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Water Supply (Water Fittings) Regulations 1999 Guidance Document relating to Schedule 1: Fluid Categories and Schedule 2: Requirements For Water Fittings [See Regulation 4(3)l

SECTION 2

Schedule 2: Paragraph 2: Materials and substances in contact with water

2. (1) Subject to sub-paragraph (2) below, no material or substance, either alone or in combination with any other material or substance or with

the contents of any water fitting of which it forms a part, which causes or is likely to cause contamination of water shall be used in the construction, installation, renewal, repair or replacement of any water fitting which conveys or receives, or may convey or receive, water supplied for domestic or food production purposes.

(2) This requirement does not apply to a water fitting downstream of a terminal fitting supplying wholesome water where-

a. the use to which the water downstream is put does not require wholesome water; and
b. a suitable arrangement or device to prevent backflow is installed.

Guidance

General

G2.1 Materials or substances, either alone or in combination, which cause, or are likely to cause, contamination of water should not used in the construction, installation, renewal, repair or replacement of any water fitting which conveys or receives water supplied for domestic or food production purposes. Particular materials unsuitable for use in contact with water intended for domestic or food production purposes include lead and bitumastic coatings derived from coal tar.

G2.2 For non-metallic materials, this requirement is deemed to be met by compliance with the appropriate British Standard, BS 6920: 'Suitability of non-metallic products for use in contact with water intended for human consumption with regard to their effect on the quality of water'. No standard of any other EEA State includes the same suite of tests, although individual tests may be considered as providing evidence for an equivalent level of performance. Further advice on the equivalence of foreign standards is available from the Water Regulations Advisory Scheme.

G2.3 Water fittings and materials for water fittings complying with paragraph 2(1) of Schedule 2 should be tested by an approved test house and the results published in approved lists.

G2.4 When water fittings or materials are specified to a British Standard or other document, the reference is to the latest available edition of the document referred to.

G2.5 The following factors should be considered when determining the suitability of materials and fittings which are, or will be, in contact with the water supplied:

a. internal and external temperatures to which they will be subjected;
b. the effect of internal and external corrosion; c. compatibility of different materials.
d. the effect of ageing, fatigue, durability and other mechanical factors; and,
e. permeability.

G2.6 Providing a suitable backflow prevention device is installed, sub- paragraph 2(1) of Schedule 2 does not apply to water fittings downstream of a terminal fitting supplying wholesome water, where the recipient use does not need to be wholesome, for example:

a. a hosepipe, used in connection with a clothes washing machine or dishwasher, or for watering a garden, or washing a vehicle, where the fitting to which the hosepipe is, or may be connected to, or incorporate, a suitable device to prevent backflow through the hosepipe; or,

b.  a flushing cistern; or
c. a  feed cistern connected to a primary heating circuit; or,
d. a closed circuit; or,
e. an overflow or warning pipe.

Stopvalves, servicing valves and drain taps

G2.7 Draw-off taps, stopvalves, servicing valves and draining taps should be designed so that, where applicable, their seals can be readily renewed or replaced; do not incorporate a loose washer plate; be designed and manufactured so that they may be easily closed to shut off the supply of water; and be capable of operating at the appropriate water temperature and pressure.

G2.8 Stopvalves of 15mm to 50mm nominal size laid underground should be screwdown valves complying with BS 5433 or plug cocks conforming with BS 2580. Stopvalves for use above ground should be screwdown valves complying with BS 1010 or as for below ground use. Stopvalves of nominal size 50mm may, and larger sizes should be cast iron gate valves complying with BS 5163. Spherical type valves may also be used in all sizes for above and below ground.

Terminal fittings

G2.9 Taps and combination tap assemblies used in water supply installations should be appropriate for the residual pressure available and the flow required at a particular appliance.

G2.10 Low resistance taps and combination tap assemblies suitable for minimum inlet pressures of 0. 1 bar (0.01 Mpa) should comply with B S 5412, or BS 1010 where appropriate, and high resistance taps and combination fittings suitable for minimum inlet pressures of 0.5 bar (0.05 Mpa) with BS EN 200 and BS 6920.

Joining of different types of materials

G2.11 Except for plastics pipes, new pipework should not be connected to existing lead or other pipework without appropriate protection being provided against galvanic corrosion.

Jointing materials and compounds

G2.12 Soft solder for capillary jointing of copper or copper alloy water fittings should consist of Tin/Copper, Alloy No. 23 or 24, or Tin/Silver, Alloy No. 28 or 29, complying with BS EN 29453.

G2.13 Silver solder or silver brazing filler metals and copper- phosphorus brazing filler metals for capillary jointing of copper or copper alloy pipes should conform to BS 1845, Table 2; Group AG (AG14 or AG20) or Table 3: Group CP (CP I to CP6), respectively,

G2.14 Silver solder or silver brazing material for capillary jointing of stainless steel pipes should be cadmium free.

G2. 1 5 Jointing compounds used for sealing screwed water fittings should comply with BS 6956: Part 5.

G2.16 Unsintered polytetrafluoroethylene (PTFE) tape for thread scaling applications should comply with B S 6974 and the material should also satisfy the requirements of BS 6920: Part 1.

2000

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