Inhibition of crack propagation in gas pipelines - by surrounding with strengthening steel rope at intervals

摘要

The propagation of cracks in gaslines is inhibited by steel rope wound around pipeline at intervals along its length so that a surrounding portion of the line has the relationship Cveq/Cva >=3 (where Cva is the Charpy energy per unit area measured transversely of the unstrengthened line and Cveq is the equiv. Charpy energy per unit area of the strengthened portions of the gasline). Steel rope is pref. wound around the gasline without applying tension to the rope which has an ultimate tensile strength of 100-200 kg/mm2 and a Young's modulus of 18,000 - 21,000 kg/mm2. Damage to gasline by the propagation of a crack is reduced and the system may be applied during gasline installations or to gaslines already in use. Gaslines with pipes of poorer quality may be utilised.