US4523141A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pipe coating
Assignee: Kendall Co
•
Filing: 1982-04-16
•
Granted: 1985-06-11
•
Expires: 2002-04-16
Abstract
Abstract Pipe coating having a thermal insulating layer of polymeric material and an outer barrier layer is provided with an additional electro-conductive layer intermediate between the two layers to facilitate testing of the latter for discontinuities by conventional electric testing equipment for detecting discontinuities in the outer barrier layer, e.g. by measuring electrical conductivity or resistivity along the face of the barrier layer.
Inventors
- 👤 Samuel J. Thomas
- 👤 James M. Robich
- 👤 Robert L. Hayes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:38
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/12; G01R31/1227; G01R31/1263; G01R31/50; G01R31/58
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
75 words
In the method of detecting pinholes and other discontinuities in the outer barrier layer of metal pipe coated with a termal insulating layer of foamed polymeric material having an irregular outer surface and an outer barrier layer of polymeric material which comprises measuring electrical conductivity or resistivity along the face of said barrier layer, the improvement which comprises interposing between and bonding to said insulating layer and said outer barrier layer an electroconductive intermediate layer.
Claim 2
Dependent Claim
75 words
In the method of detecting pinholes and other discontinuities in the outer barrier layer of metal pipe coated with a termal insulating layer of foamed polymeric material having an irregular outer surface and an outer barrier layer of polymeric material which comprises measuring electrical conductivity or resistivity along the face of said barrier layer, the improvement which comprises interposing between and bonding to said insulating layer and said outer barrier layer an electroconductive intermediate layer.
References Cited (Backward Citations)
US2056085A
Cited
US2857931A
Cited
DE1164566B
Cited
US3420277A
Cited
US3731710A
Cited
US3992237A
Cited
US3719884A
Cited
US3807458A
Cited
SU381045A1
Cited
DE2320282A1
Cited
US4197423A
Cited
SU725006A1
Cited
DD151660A1
Cited
DE3024563A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-10 | 1988-12-10 | 1989-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-10 | 1992-12-10 | 1993-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-10 | 1996-12-10 | 1997-06-11 | $7700.00 | Window Closed / Lapsed |