Process for lining metal pipelines

摘要

A process for lining a metal pipeline, which process generally utilizes thermoplastic fluoropolymer pipe liner Also, a pipeline system that includes at least two coaxial pipes, an outer metal pipe and inner thermoplastic fluoropolymer pipe. The thermoplastic fluoropolymer pipe/pipe liner is made from a composition that generally includes from 10% to 60% by weight of at least one vinylidene fluoride (VDF) homopolymer, from 40% to 90% by weight of at least one VDF copolymer comprising from 2% to 15% by moles of recurring units derived from at least one other fluorinated comonomer (F), and optionally at least one plasticizer.

主权项

1. A process for lining a metal pipeline, said process comprising the following steps:
(i) processing a thermoplastic fluoropolymer composition to yield a pipe liner having an outer diameter greater than the inner diameter of said metal pipeline, said thermoplastic fluoropolymer composition comprising:
(A) from 10% to 60% by weight, based on the total weight of polymer A and polymer B, of at least one polymer A, wherein polymer A is a vinylidene fluoride (VDF) homopolymer,(B) from 40% to 90% by weight, based on the total weight of polymer A and polymer B, of at least one polymer B, wherein polymer B is a VDF copolymer comprising from 2% to 15% by moles of recurring units derived from at least one other fluorinated comonomer F, and optionally, (C) at least one plasticizer; (ii) deforming said pipe liner to yield a deformed pipe liner having an outer diameter smaller than the inner diameter of said metal pipeline; (iii) introducing the deformed pipe liner in said metal pipeline; and (iv) expanding the deformed pipe liner to fit with the inner diameter of said metal pipeline.