FLEXIBLE TUBULAR STRUCTURE, METHOD OF MOULDING SUCH STRUCTURE, METHODS OF MOULDING SPIRAL MEMBER AND CONNECTING IT WITH TUBULAR STRUCTURE Russian patent published in 1998 - IPC

FIELD: manufacture of tubular structures. SUBSTANCE: tubular structure, for example pipe or reservoir, has wall made from plastic, composite or polymer materials. Composite materials are spirally wound and are separated by elastomer strips. Wall has inner member formed by continuous flexible plastic cylinder with spiral projection on its outer surface. Outer layer is made from alternating spirally wound composite or elastomer strips. Composite strip has projection directed radially inside and located axially at some distance from projection on plastic cylinder. Cylinder and layer are separated by intermediate layer made from composite and elastomer strips. Composite strip is laid between each pair of adjacent projections and is separated from them by elastomer strip. Outer wall member is made from alternating spirally wound composite and elastomer strips; winding pitch of elastomer strips exceeds inner wall member. EFFECT: enhanced reliability. 23 cl, 25 dwg, 2 tbl