Flange connection assembly for fiber-reinforced plastic pipe members

A flange connection assembly for fiber-reinforced plastic pipe members comprising:

• a pair of pipe members joined together, said pipe members each comprising an inner pipe jacket consisting essentially of thermoplastic material and an outer pipe jacket consisting essentially of a fiber winding impregnated with a synthetic resin;
• a threaded section consisting essentially of rounded threads formed in said outer pipe jacket at the end of each of said pipe members;
• a flange bushing including a loose flange ring and having rounded threads formed on said bushing threadedly engaged on each of said threaded sections of said outer pipe jacket;
• and
• a covering collar covering at least the end of each of said pipe members inserted at said inner pipe jacket, said covering collar consisting essentially of a cylindrical portion extending into engagement internally into said inner pipe jacket joined with said inner jacket by a bonded connection which is fluid tight;
• said covering collar being fabricated of the same material as said inner pipe jacket and coextending in engagement therewith to at least partially overlap with said flange bushing;
• said flange bushing consisting essentially of a fiber winding impregnated with synthetic resin and being solidly connected with said pipe members in said threaded section by means of a bonded connection.