NF T57-220*NF EN 1228:1996 Plastics piping systems. Glass-reinforced thermosetting plastics (grp) pipes. Determination of initial specific ring stiffness.
1996NF T57-220*NF EN 1228:1996 Plastics piping systems. Glass-reinforced thermosetting plastics (grp) pipes. Determination of initial specific ring stiffness.