This British Standard specifies requirements for semi-rigid (bendable) corrugated stainless steel pipe and associated fittings in the nominal size range DN 10 to DN 50 and intended for use as installation pipework for the supply of 1st, 2nd and 3rd family gases in permanent buildings. It applies to corrugated pipe and fittings which are suitable for a maximum working pressure of 75 mbar when installed in accordance with BS 6891 or BS 5482-1 in domestic premises, or in accordance with the Institution of Gas Engineers publication IGE/UP/2 [1] in other premises. Requirements for the protection of the outer surface of the corrugated pipe by a coating or a cover are included.
Corrugated stainless steel semi-rigid pipe to this standard is not intended for applications in which during installation, or subsequent to installation, it can be subjected to repeated bending (see A.5).
Information to be provided in the installation instructions is specified in Annex A.
Annex B gives guidance on the nature of the requirements and test methods, to assist in the preparation of quality plans for the manufacture of corrugated pipe and fittings.
Annex C gives the suggested sizes of fittings.
NOTE 1 A typical method of installation, using corrugated pipe and fittings conforming to this standard, is to connect the meter outlet to a centrally placed manifold by the use of suitably sized corrugated pipe. Each appliance can then be connected directly to the manifold, again by the use of suitably sized corrugated pipe. Alternatively, for small installations, tees can be used. As the corrugated pipe can be readily bent to the required shape, bend and sweep fittings are generally not required.
NOTE 2 The threaded end-fittings covered by this standard are required to conform to BS 21 (see 6.4) and are therefore suitable for use in conjunction with fittings to BS 143 & 1256 or BS EN 10242 which have jointing threads in accordance with BS 21.
NOTE 3 Attention is drawn to the possibility of restricted access on site and the need to consider the application of forces and torques required for assembly, particularly for larger diameters, when designing and planning the installation.