Patent ID: 6287657
Filing Date: 2001-09-11
Classification: F16L,Y10T

Abstract:
A flexible all plastic air feeder pipe through which air is blown to conduits in which are placed electrical communication cables, the air keeping water vapor or moisture away from the cables and the air feeder pipe being of large enough diameter to accomodate the air flow to the conduits but which diameter increases the surface area of the air feeder pipe through which water vapor may cross from the outer surface of the air feeder pipe into the air within the air feeder pipe, said air feeder pipe comprising:a continuous outer tubular pipe having an inner surface and comprising a material having a low tensile modulus and a first permeability coefficient; andmeans for preventing the water vapor or moisture from crossing from the outer surface of said tubular pipe into the air being distributed by said tubular pipe into the conduits, said means consisting of a continuous inner tubular moisture barrier directly affixed to said inner surface of said outer tubular pipe and coextensive therewith, said tubular moisture barrier having a second permeability coefficient at least an order of magnitude lower than said first permeability coeffcient;said all plastic air feeder pipe being of the same construction over its entire length; andwherein said outer tubular pipe has a nominal inside diameter of at least one inch and said outer tubular pipe and said inner tubular moisture barrier have thicknesses so as to meet the relationship of the permeability coefficients of said outer tubular pipe and said tubular moisture barrier.