Method of thermally insulating pipe

Claim 1

A METHOD OF THERMALLY INSULATING PIPE, WHICH COMPRISES CONTINUOUSLY ROTATING THE PIPE ABOUT A SUBSTANTIALLY HORIZONTAL AXIS WHILE ADVANCING THE PIPE AT A UNIFORM SPEED LONGITUDINALLY THROUGH A FIRST POSITION, FROTHING ONTO AN UPPER REGION OF THE SURFACE OF THE PIPE AT SAID FIRST POSITION A PLASTIC FOAM MIX SO AS TO COAT SAID SURFACE PROGRESSIVELY ALONG ITS LENGTH, CONFINOUSLY FORMING AT A SECOND POSITION ADJACENT TO THE FIRST POSITION A METAL TUBE OF LARGER DIAMETER THAN THE PIPE, THE METAL TUBE BEING FORMED COAXIALLY WITH THE PIPE BY CONTINUOUSLY FEEDING A PREHEATED METAL STRIP HAVING PARALLEL EDGES IN A DIRECTION TRANSVERSE TO SAID AXIS AND CONTINUOUSLY COALING THE STRIP ALONG A HELICAL PATH WHILE JOINING TOGETHER THE EDGES OF ADJACENT CONVOLUTIONS OF THE STRIP TO FORM A MOISTURE-PROOF HELICAL SEAM, CONTINUOUSLY ADVANCING THE TUBE AT SAID UNIFORM SPEED LONGITUDINALLY FROMSAID SECOND POSITION TO DEFINE BETWEEN THE PIPE SURFACE AND THE TUBE AN ANNULAR SPACE, AND MAINTAINING THE PIPE AT A TEMPERATURE AT WHICH THE MIX CONSTITUENTS WILL REACT TO FORM A FOAMED MASS ENVELOPING THE PIPE AND FILLING SAID ANNULAR SPACE.

Claim 2

A METHOD OF THERMALLY INSULATING PIPE, WHICH COMPRISES CONTINUOUSLY ROTATING THE PIPE ABOUT A SUBSTANTIALLY HORIZONTAL AXIS WHILE ADVANCING THE PIPE AT A UNIFORM SPEED LONGITUDINALLY THROUGH A FIRST POSITION, FROTHING ONTO AN UPPER REGION OF THE SURFACE OF THE PIPE AT SAID FIRST POSITION A PLASTIC FOAM MIX SO AS TO COAT SAID SURFACE PROGRESSIVELY ALONG ITS LENGTH, CONFINOUSLY FORMING AT A SECOND POSITION ADJACENT TO THE FIRST POSITION A METAL TUBE OF LARGER DIAMETER THAN THE PIPE, THE METAL TUBE BEING FORMED COAXIALLY WITH THE PIPE BY CONTINUOUSLY FEEDING A PREHEATED METAL STRIP HAVING PARALLEL EDGES IN A DIRECTION TRANSVERSE TO SAID AXIS AND CONTINUOUSLY COALING THE STRIP ALONG A HELICAL PATH WHILE JOINING TOGETHER THE EDGES OF ADJACENT CONVOLUTIONS OF THE STRIP TO FORM A MOISTURE-PROOF HELICAL SEAM, CONTINUOUSLY ADVANCING THE TUBE AT SAID UNIFORM SPEED LONGITUDINALLY FROMSAID SECOND POSITION TO DEFINE BETWEEN THE PIPE SURFACE AND THE TUBE AN ANNULAR SPACE, AND MAINTAINING THE PIPE AT A TEMPERATURE AT WHICH THE MIX CONSTITUENTS WILL REACT TO FORM A FOAMED MASS ENVELOPING THE PIPE AND FILLING SAID ANNULAR SPACE.

Claim 3

A method of thermally insulating pipe, which comprises continuously rotating the pipe about a substantially horizontal axis while advancing the pipe at a uniform speed longitudinally through a first position, frothing onto an upper region of the surface of the pipe at said first position a plastic foam mix so as to coat said surface progressively along its length, continuously forming at a second position adjacent to the first position a metal tube of larger diameter than the pipe, the metal tube being formed coaxially with the pipe by continuously feeding a galvanized sheet steel strip having parallel edges in a direction transverse to said axis and continuously coiling the strip along a helical path while joining together the eDges of adjacent convolutions of the strip to form a moisture-proof helical seam, continuously advancing the tube at said uniform speed longitudinally from said second position to define between the pipe surface and the tube an annular space, and maintaining the pipe at a temperature at which the mix constituents will react to form a foamed mass enveloping the pipe and filling said annular space.

Claim 4

A method of thermally insulating pipe, which comprises continuously rotating the pipe about a substantially horizontal axis while advancing the pipe at a uniform speed longitudinally through a first position, frothing onto an upper region of the surface of the pipe at said first position a plastic foam mix so as to coat said surface progressively along its length, continuously forming at a second position adjacent to the first position a metal tube of larger diameter than the pipe, the metal tube being formed coaxially with the pipe by continuously feeding a galvanized sheet steel strip having parallel edges in a direction transverse to said axis and continuously coiling the strip along a helical path while joining together the eDges of adjacent convolutions of the strip to form a moisture-proof helical seam, continuously advancing the tube at said uniform speed longitudinally from said second position to define between the pipe surface and the tube an annular space, and maintaining the pipe at a temperature at which the mix constituents will react to form a foamed mass enveloping the pipe and filling said annular space.