Pipe insulator and method for making same

An electrically insulated pipe coupling comprising:

• a first sleeve member and a second sleeve member positioned in axial alignment and including oppositely positioned end portions axially spaced from one another to create an axial space therebetween;
• a resilient annular seal portion gradually formed in situ in said axial space, aid seal portion chemically bonding to said oppositely positioned end portions whereby said seal portion provides a low pressure coupling seal between said first and second sleeve members;
• an outer protective layer comprising of continuous synthetic resin saturated fiberglass strand windings encircling at least a portion of the end portions of said first and second sleeve members and encircling all of said annular seal portion, said outer protective layer including radially innermost windings which are provided in a closely spaced hoop winding pattern;
• and
• a rigid reinforcing sleeve embedded in and covered by said fiberglass windings of said outer protective layer.

An electrically insulated pipe coupling comprising:

• a first sleeve member and a second sleeve member positioned in axial alignment and including oppositely positioned end portions axially spaced from one another to create an axial space therebetween;
• a resilient annular seal portion gradually formed in situ in said axial space, said seal portion chemically bonding to said oppositely positioned end portions whereby said seal portion provides a low pressure coupling seal between said first and second sleeve members;
• an outer protective layer comprising of continuous synthetic resin saturated fiberglass strand windings encircling at least a portion of the end portions of said first and second sleeve members and encircling all of said annular seal portion, said outer protective layer including radially outermost windings which are provided in a widely spaced helical winding pattern;
• and
• a rigid reinforcing sleeve embedded in and covered by said fiberglass windings of said outer protective layer.

A method for making an electrically insulated pipe coupling comprising the steps of:

• positioning and securing a first sleeve member and a second sleeve member in axial alignment onto a mandrel with end portions of said first and second sleeve members axially spaced from one another with an axial space therebetween through which said mandrel fully extends;
• rotating said mandrel and said secured sleeve members;
• applying a liquid urethane material onto said rotating end portions and onto said mandrel which extends through said axial space to gradually form a resilient seal portion between said end portions thereby joining said end portions together in a sealing engagement;
• encircling said end portions and said seal portion with continuous synthetic resin saturated fiberglass strand windings to form an outer protective layer;
• and
• placing a rigid reinforcing sleeve onto said outer protective layer when said layer is partially formed and thereafter completing the formation of said outer protective layer whereby said rigid reinforcing sleeve is embedded in and covered by said fiberglass windings of said outer protective layer.