Electric heating apparatus for de-icing pipes

Claim 1

Apparatus for heating liquid-carrying pipes to prevent freezing of the liquid and thawing of frozen liquid in the pipes, said apparatus comprising: (a) a housing having a lateral passageway and a central bore connected to an opening at each end of the housing and to the passageway, each end of the housing being provided with external threads and a fitting for sealingly attaching the housing to the open end of a liquid pipe, so that the bore of the housing is effective to connect the open end of a first pipe to the open end of a second pipe, each of said fittings comprising: (1) a sleeve that is attachable to the end of the pipe and has an outwardly extending annular flange, (2) a sealing gasket between the annular flange and the end of the housing, and (3) a coupling nut provided with internal threads for threadingly and engaging the external threads of the housing and an inwardly extending annular flange for engaging and outwardly extending flange of the sleeve, (b) a sealer valve for sealing the passageway and having an opening with a normally closed penetrable seal of elastomeric material adapted to slidably receive an elongated continuous element and to permit said element to move axially through the valve in a sealed relationship, (c) electrical control means being mounted on the exterior of the housing and adapted to receive electrical power, and (d) an elongated heating cable having a first and electrically connected to the control means to receive power therefrom and having a second free end slidably insertable through the penetrable seal of the sealer valve through the passageway into the housing bore and then into one of the pipes through the open end thereof, said cable being provided with a heating element for receiving power through the cable from the control means.