BS 7531:2006 pdf download – Rubber bonded fibre jointing for industrial and aerospace purposes – Specification
4 Information to be supplied by purchaser
The following information to be supplied by the purchaser shall be fully documented. For compliance with the standard both the definitive requirements specified throughout the standard and the following documented items shall be satisfied.
a) the number of this British Standard, i.e. BS 7531:2006 (see 10.1);
b) for Grades AX and AY the fibre type (see 5.2);
c) the grade of jointing required (see Scope);
d) the thickness required (see 7.1);
e) the dimensions of sheets required;
f) the quantity of sheets required;
g) if wire mesh reinforcement is required and, if so the wire material,diameter and mesh size (see 5.3);
h) if the jointing will or is likely to come into contact with potable water (see 5.4);
i) if the manufacturer’s identification mark is not required to be indelibly marked on the jointing (see 10.3);
j) for Grades AX and AY if a test certificate is required (see 11.1);
k) if one or both surfaces shall be treated with a suitable release agent, e.g. graphite (see Clause 6).
5 Grades and materials
For grades AX and AY the binder shall be acrylonitrile-butadiene (NBR) elastomer.
The material shall consist of fibres and inorganic fillers bonded with a suitable elastomer or blend of elastomers, and shall be manufactured in the form of sheets. The fibres shall be uniformly dispersed throughout the jointing. For Grades AX and AY the purchaser shall state which fibre type is required.
5.3 Reinforcement All grades shall be available with or without wire mesh reinforcement. The purchaser shall state if wire mesh reinforcement is required and the wire material, diameter and mesh size should be specified.
5.4 Contact with potable water When used under the conditions for which they are designated, non-metallic products in contact with or likely to come into contact with potable water shall comply with the requirements of BS 6920-1.
NOTE 1 Non-metallic products for installation and use in the United Kingdom which are verified and listed under the UK Water Fitting Byelaws Scheme are deemed to satisfy the requirements of this clause. Details of the Scheme are obtainable from WRC plc, 660 Ajax Avenue, Slough SL1 4BG.
NOTE 2 Non-metallic products 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 adverse health effects for the purposes of compliance with this clause. A list of approved chemicals and materials and details of the approvals scheme are available from the Secretary of the Committee at the Department of the Environment, Water Division, Romney House, 43 Marsham Street, London SW1P 3PY. The purchaser shall state whether, when used under the conditions for which they are designated, non-metallic products come or are likely to come into contact with potable water.
6 Finish The sheets of all grades of jointing shall be solid run (not laminated), of uniform texture, smooth on both sides and free from irregularities such as blisters, tears and lumps. The purchaser shall state whether, and which, surfaces shall be treated with an acceptable release agent, e.g. graphite.
7.1 Nominal thickness
The nominal thickness of all grades of jointing shall be one of the following:
a) 0.4 mm;
b) 0.5 mm;
c) 0.75 mm;
d) 1.0 mm;
e) 1.5 mm;
f) 2.0 mm.
NOTE For any grade of material the compressive strength at elevated temperature decreases with increasing thickness.
The purchaser shall state the thickness required.
7.2 Thickness tolerance The maximum variation of any sheet from the nominal thickness, and the maximum possible variation in thickness between any points not more than 250 mm apart on a sheet, shall be in accordance with Table 1.BS 7531 pdf download.