This standard specifies methods for determining the initial specific ring stiffness of glass-reinforced thermosetting plastics (GRP) pipes. Two methods are given and within the specified deflection limits each is equally valid and may be used for any diameter.
BS EN 1228:1997 history
1997BS EN 1228:1997 Plastics piping systems. Glass-reinforced thermosetting plastics (GRP) pipes. Determination of initial specific ring stiffness