This document, which is a guidance document for use with a structural analysis procedure for below groundinstallations, covers limits applicable to glass-reinforced thermosetting plastics (GRP) pipes used for the conveyance of liquids under pressure or gravity conditions.
This document does not specify a particular structural analysis procedure but gives guidance on the selection of a structural analysis procedure. It concludes that any established structural analysis procedure may be used provided it includes the assessment of short and long-term deflection and buckling resistance.
NOTE 1 Products complying to the applicable system standards (prEN 1796 or prEN 14364), which are not subject to internal pressure, are suitable as long as the analysis shows that the long-term deflection of the installed pipes is limited to 6 %, which is the basic assumption of the system standards. Similarly products complying with the applicable system standards (prEN 1796 or prEN 14364), which are subject to internal pressure, are suitable as long as the analysis shows that the initial and long-term deflection of the installed pipes does not exceed 3 %.
NOTE 2 The approach followed when preparing a structural analysis procedure in general does not depend on the nominal size(s) of the pipe(s).
NOTE 3 A suitable structural analysis procedure would normally be capable of being used for pipes operating at different temperatures provided that the corresponding temperature re-rating factors for the relevant pipe properties are applied, as specified in the referring standard(s). Nevertheless, high service temperatures may require an additional analysis of the longitudinal stresses and strains and/or a special design of the joints.