Double spiral-wound gasket assembly with leak detection

A flange assembly for detecting the leakage of process fluid between the flanges of a process unit connection or pipeline, said flange assembly comprising a gasket assembly comprising from an inner to an outer diameter:

• a) an inner compression gauge ring having an inner edge and an outer edge;
• b) a first spiral-wound gasket having an inner and an outer winding, said inner winding wrappingly abutting the outer edge of said inner compression gauge ring;
• c) a middle compression gauge ring having an inner and an outer edge, said inner edge abutting the outer winding of said first spiral-wound gasket and having a centrally located groove in both an upper face and a lower face of said middle compression ring for collecting fluid leakage past said first spiral-wound gasket said centrally located groove having drawoff ports therethrough, whereby fluid flow past said gasket can be monitored by a sensing device;
• d) a second spiral-wound gasket having an inner and an outer winding, said inner wrappingly abutting the outer edge of said second spiral-wound gasket;
• and
• e) an outer compression gauge ring, having an inner and an outer edge, said inner edge abutting the outer winding of said second spiral-wound gasket.

A method fop detecting process fluid leakage between flanges of a process unit or pipeline, comprising the steps of:

• a) affixing between a pair of opposing flanges a double spiral-wound gasket assembly comprising from an inner to an outer diameter;
• 1) an inner compression gauge ring having an inner and an outer edge;
• 2) a first spiral-wound gasket having an inner and an outer winding, said inner winding wrappingly abutting the outer edge of said inner compression gauge ring;
• 3) a middle compression gauge ring having an inner and an outer edge, said inner edge abutting the outer winding of said first spiral-wound gasket and having a centrally located groove in both an upper face and a lower face of said middle compression ring for collecting fluid leakage past said first spiral-wound gasket said centrally located grooves having drawoff ports therethrough whereby fluid collected in said grooves can be monitored by a sensing device;
• 4) a second spiral-wound gasket having an inner and an outer winding, said inner winding wrappingly abutting the outer edge of said middle compression ring;
• and
• 5) an outer compression gauge ring, having an inner and an outer edge, said inner edge abutting the outer winding of said second spiral=wound gasket.
• b) purging said gasket assembly with a purge carrier fluid;
• and
• c) analyzing said purge carrier fluid.