Patent ID: 6042120
Filing Date: 2000-03-28
Classification: F16L

Abstract:
Apparatus for producing a controlled freeze seal in a fluid-filled pipe, comprising:a reservoir of a coolant;a tube connected to said reservoir and extending along the pipe in contact with it;a valve inserted into said tube between said reservoir and the pipe for controlling the flow of coolant through said tube;a temperature sensor in thermal contact with the pipe at the location of the seal for sensing the temperature T of the pipe at the seal;a temperature controller connected to said valve and to said temperature sensor, and responsive to the sensed temperature T and to a preset desired temperature T.sub.D for controlling the flow of coolant through said tube, where T.sub.D is a temperature that is low enough to maintain the fluid in the pipe in a frozen condition and high enough to prevent damage to the metallurgical structure of the pipe.