Method of lining metal pipe

Abstract

Abstract A METHOD OF LINING METAL PIPE WITH A TUBE OF RIGID THERMAL-PLASTIC MATERIAL HAVING AN OUTER DIAMETER SLIGHTLY SMALLLER THAN THE INNER DIAMETER OF THE PIPE. THE TUBE IS COATED WITH AN EPOXY CEMENT AND INSERTED AXIALLY INTO THE PIPE. AIR IS WITHDRAWN FROM THE SPACE BETWEEN THE PIPE AND THE TUBE TO CREATE A VACUUM IN THIS SPACE. HOT OIL AT A TEMPERATURE OF ABOUT 285 DEGREES FAHRENHEIT IS THEN FLOWED THROUGH THE TUBE STARTING FROM ONE END OF THE TUBE AT AN INLET PRESSURE OF 1-5 POUNDS PER SQUARE INCH AND DISCHARGING OUT THE OTHER END OF THE TUBE TO ATMOSPHERIC PRESSURE FOR A TIME LONG ENOUGH TO RAISE THE TEMPERATURE OF THE TUBE PROGRESSIVELY FROM THE OIL INLET END OF THE TUBE TO THE OIL OUTLET END OF THE TUBE TO CHANGE THE STATE OF THE TUBE FROM RIGID TO PLASTIC. THE VACUUM CAUSES THE TUBE TO EXPAND OUTWARDLY PROGRESSIVELY FROM ONE END OF THE PIPE TO THE OTHER AS IT IS CHANGED TO A PLASTIC STATE BY THE OIL AND THE PROGRESSIVE EXPANSION CAUSES RESIDUAL AIR TO BE SQUEEZED OUT FROM BETWEEN THE TUBE AND PIPE. THE VACUUM IS MAINTAINED WHILE THE FORMED TUBE IS COOLED, THE TUBE BEING CEMENTED TO THE PIPE BY THE EPOXY CEMENT. A SWAB MAY BE PUSHED THROUGH THE COOLED TUBE AND PIPE TO FURTHER COOL THE TUBE AND TO REMOVE OIL ADHERING TO THE INSIDE OF THE TUBE.

Inventors

• 👤 Willard B Kimbrell
• 👤 Sol B Kimbrell

Bibliographic Details