1.1 This specification covers axially unrestrained bell-and-spigot gasket joints including couplings required for machine-made “fiberglass” (glass-fiber-reinforced ther This specification covers axially unrestrained bell-and-spigot gasket joints including couplings required for machine-made "fiberglass" (glass-fiber-reinforced thermosetting-resin) pipe systems, 8 in. (200 mm) through 144 in. (3700 mm), using flexible