Increased pressure fluid carrying pipeline system and method therefor

Abstract

A method of maximizing system operating pressure capability of a selected flange joint in a fluid carrying pipeline system comprises minimizing bold load operating conditions and bolt load pre-load conditions at the selected flange joint by interposing a self-energizing seal assembly having negligible 'm' and 'y' values in surrounding relation to the joint's axial bore. The load producing moment resulting from connection of the flanges with the bolts is minimized by interposing a gasket element having a gasket thickness less than the seal thickness of the self-energizing seal assembly. The gasket element is interposed in a surrounding relation to the seal assembly at an outer radial location proximate to the outer flange surface margin. The flanges are connected with the bolts to form the flange joint while supporting the self-energizing seal assembly and the gasket element at the inner and outer radial locations, respectively, thereby to compress the self-energizing seal from the seal thickness to the gasket thickness. A method is also provided for forming a high pressure fluid carrying pipeline system adapted to convey a fluid at a system pressure of at least 1000 PSI. A high pressure fluid carrying pipeline system is also provided which broadly comprises a plurality of joined pipeline sections, a seal device including a self-energizing seal assembly interposed between flange pairs, a rigid gasket element in surrounding relation to each seal assembly, a plurality of nut and bolt sets interconnecting the flanges with the seal assembly compressed therebetween and a fluid disposed in the axial bore.