Method of installing a new pipe inside an existing conduit by progressive rounding
AssigneeNuPipe, Inc.
InventorCampbell H. Steketee, Jr.
Life of this patent
Estimating the term…
Abstract
A thin, flexible tubular membrane provides a heat containment tube for inserting into and inflation within an underground conduit to be repaired. Folded rigid thermoplastic pipe is inserted into the tube while not and flexible. The tubular membrane is pressurized to exclude unwanted fluids from within the existing conduit. Hot steam is injected into the tube to heat the pipe full-length externally and internally until flexible. The pipe is then rounded and expanded against the walls of the conduit with the tube therebetween. The rounding and expanding of the pipe is carried out progressively by moving a plug through the pipe and by injecting hot steam under pressure behind the plug.
Claims18
A method of installing a new pipe inside a length of existing conduit comprising the steps:
- inserting within the length of the conduit a length of normally rigid thermoplastic pipe while in a collapsed condition of reduced diameter,
- heating at least one end portion of the collapsed pipe to render it flexible, rounding said end portion, and inserting a traveling plug within the rounded end portion, with such traveling plug enabling the restricted passage of pressurized fluid therepast through the collapsed pipe,
- restraining the traveling plug against movement through the thermoplastic pipe from the rounded end portion,
- injecting a hot fluid under pressure into said end portion until a length of the collapsed thermoplastic pipe ahead of the plug becomes heated and flexible, and
- allowing the traveling plug to advance at a controlled speed through the pipe from the rounded end portion while continuing to inject hot fluid under pressure into the pipe behind the plug to progressively reform the length of pipe to a rounded shape as the plug travels through the pipe.
A method of installing a new pipe inside a length of existing conduit comprising the steps:
- inserting within the length of the conduit a length of normally rigid thermal plastic pipe while in a collapsed condition of reduced diameter within a thin, flexible tubular member extending the length of the conduit with the tubular member in an expanded rounded condition,
- heating at least one end portion of the collapsed pipe to render it flexible, rounding said end portion, and inserting a traveling plug within the rounded end portion, with such traveling plug enabling the restricted passage of pressurized fluid therepast through the collapsed pipe,
- restraining the traveling plug against movement through the thermoplastic pipe from the rounded end portion,
- injecting a hot fluid under pressure into said end portion until a length of the collapsed thermoplastic pipe ahead of the plug becomes heated and flexible, and
- allowing advancement of the traveling plug at a controlled speed through the pipe from the rounded end portion while continuing to inject hot fluid under pressure into the pipe behind the plug to progressively reform the length of pipe to a rounded shape as the plug travels through the pipe.
A method of installing a new pipe inside a length of existing conduit comprising the steps:
- inserting within the length of the conduit a length of normally rigid thermoplastic pipe while in a collapsed condition of reduced diameter,
- heating at least one end portion of the collapsed pipe to render it flexible, expanding said end portion, and inserting a traveling plug within the expanded end portion, with such traveling plug enabling the restricted passage of pressurized fluid therepast through the collapsed pipe,
- restraining the traveling plug against movement through the thermoplastic pipe from the expanded end portion,
- injecting a hot fluid under pressure into said end portion until a length of the collapsed thermoplastic pipe ahead of the plug becomes heated and flexible, and
- allowing the traveling plug to advance at a controlled speed through the pipe from the expanded end portion while continuing to inject hot fluid under pressure into the pipe behind the plug to progressively reform the length of pipe to a expanded shape as the plug travels through the pipe.
Dependencies are inferred from the claim text.