US Patent 7581565 Tear cord for jacketed tube

The disclosure pertains to installing a tear cord between a metal tube and a protective jacket. The jacketed tubes may be used in a hydrocarbon production downhole well bore. The tubes may be used to furnish hydraulic fluid or chemicals into the well bore. The contents may be pressurized or under vacuum. The jacketed tubes are hermetically sealed. The tubes, which may be 1 inch in diameter, are joined using compression fittings. Tear cords are used to facilitate removal of the protective jacket without damage to the tube surface thereby facilitating the placement of compression fittings and maintaining the integrity of the tube wall.