Apparatus and method for detecting and measuring localized areas of deterioration on the interior of tubes

Claim 1

A probe for use in apparatus in detecting, measuring the extent of and locating localized deteriorated areas on the interior of tubes, said probe being an elongated cylindrical member having an axially extending recessed center section of substantially lesser diameter than and lying between two axially extending end portions, said probe containing an internal passage extending from the outer end of one of said end sections to an aperture in said recessed center section, and a narrow baffle ring extending outwardly transversely of said center section between said aperture and the other one of said end sections, the diameters of said end sections and baffle ring being closely equal, said outer end section containing at least one opening extending between said recessed center section and the outer end of said other end section, said baffle ring having a circumferential cross section tapering from a thicker portion at the juncture with said recessed center section to a thin portion extending circumferentially of the outer tip.

Claim 16

A method of detecting, measuring the extent of and locating localized defects on the interior wall of tubing comprising the steps of: (a) into a base standard test tube having an unflawed interior with a diameter equal to that of a tube of the type being tested inserting a pneumatic probe adapted to pass along the length of said standard test tube and comprising an elongated cylindrical member having an axially extending portion at one end of a diameter closely matching the interior diameter of said basic standard test tube, said one end portion adjoining a substantially lesser diameter baffle chamber portion connected by an internal passage to a source of gas pressure and a baffle ring of substantially the same diameter as said one end portion and extending transversely of and outwardly from said baffle chamber portion, said baffle ring having a circumferential cross section tapering from a thicker portion at the juncture with said lesser diameter baffle chamber portion to a thin outer rim; (b) directing a flow of gas from said source at a predetermined flow rate into said probe baffle chamber and across the sharp edged orifice established between the thin outer edge of said baffle ring and the basic standard test tube interior wall: (c) measuring the back pressure established between said flow limiting device and said probe during step (b) and recording the measured back pressure of said basic standard test tube as a zero based value, (d) inserting said probe into additional flawless test tubes having internal diameters of increasing size increments over that of said base standard test tube and measuring and recording the increased back pressure established by each said additional test tube with relationship to said standard tube zero based value, (e) inserting said probe into one end of a potentially flawed tube to be inspected and drawing said probe along the length of said inspected tube and (f) recording the back pressures established between said flow limiting device and probe along each increment of length of the inspected tube with relationship to the back pressures generated in steps (c) and (d).

Claim 17

A method of detecting, measuring the extent of and locating localized defects on the interior wall of tubing comprising the steps of: (a) into a base standard test tube having an unflawed interior with a diameter equal to that of a tube of the type being tested inserting a pneumatic probe adapted to pass along the length of said standard test tube and comprising an elongated cylindrical member having an axially extending portion at one end of a diameter closely matching the interior diameter of said basic standard test tube, said one end portion adjoining a substantially lesser diameter baffle chamber portion connected by an internal passage to a source of gas pressure and a baffle ring of substantially the same diameter as said one end portion and extending transversely of and outwardly from said baffle chamber portion, said baffle ring having a circumferential cross section tapering from a thicker portion at the juncture with said lesser diameter baffle chamber portion to a thin outer rim; (b) directing a flow of gas from said source at a predetermined flow rate into said probe baffle chamber and across the sharp edged orifice established between the thin outer edge of said baffle ring and the basic standard test tube interior wall: (c) measuring the back pressure established between said flow limiting device and said probe during step (b) and recording the measured back pressure of said basic standard test tube as a zero based value, (d) inserting said probe into additional flawless test tubes having internal diameters of increasing size increments over that of said base standard test tube and measuring and recording the increased back pressure established by each said additional test tube with relationship to said standard tube zero based value, (e) inserting said probe into one end of a potentially flawed tube to be inspected and drawing said probe along the length of said inspected tube and (f) recording the back pressures established between said flow limiting device and probe along each increment of length of the inspected tube with relationship to the back pressures generated in steps (c) and (d).

Claim 20

The method of claims 14 or 15 wherein a predetermined flow rate is established into said probe by passing the air flowing from said source to said probe through a constant flow limiting device.