Abstract: A tandem seal device is provided for interposing and compressing between joined pieces of pipe in a flow line to prevent fluid leakage therebetween. The tandem seal device comprising a retainer body having an inner pair and an outer pair of continuous grooves. A first pair of seal elements, fabricated from a first material, being disposed in the inner pair of grooves. A second pair of seal elements, fabricated from a second material, being disposed in the outer pair of grooves.

Abstract: A seal device is adapted to be interposed and compressed between joined pieces in a flow line that is operative to convey a flowing fluid. The seal device comprises an inner seal member and an outer seal retainer member. The inner seal member has a central opening extending therethrough to accommodate the flow of the fluid and has a channel structure that provides a channel opening which faces the central opening and extends therearound. A pair of lips are disposed opposite each other and extend around an inner peripheral portion of the inner seal member. The lips operate to apply a sealing force against the joined pieces when interposed and compressed therebetween. The outer seal retainer member surrounds the inner seal member. The inner seal member and the outer seal retainer member are sized and adapted to seal a space between the joined pieces in the flow line when interposed and compressed between the joined pieces to allow fluid to flow therethrough.

Abstract: A protective seal and method for protecting flow line joints from leakage of fluid conveyed thereby when exposed to elevated temperatures, such as fire, employs the use of intumescent material and a channeling structure for channeling the intumescent material into a separation gap caused by thermal separation of adjacent flow line pieces, e.g., pipe sections. The channeling structure may be a channel formed in the connecting flanges, or in a gasket interposed between the pieces. Alternatively, the channeling structure may be an annulus for directing the intumescent material radially inwardly into the separation gap or a channeling strip in a spiral wound gasket. Where a channel is provided in the flange or gasket, a seal element may be used, and the intumescent material material provides a driving force to advance the seal into the separation gap. The intumescent material material may be bounded by a diaphragm or contained within a bladder.

Abstract: An isolation gasket is provided for interposition between joined pieces of a flow line. The gasket has a gasket body which electrically isolates the pieces from one another. In one embodiment the gasket has a pair of composite, insulative linings laminated on opposite sides of a metal core. An endless channel on each side of the gasket body surrounds a central flow opening and is formed of a depth sufficient to extend through the insulative lining and into the metal core. The outer sidewall of each endless channel is at an acute angle to its bottom wall, and the inner sidewall is at an angle of at least ninety degrees with respect to the bottom wall. The channels may be opposed to or offset from one another. Different channel cross-sections are described. An alternative gasket body may eliminate the metal core and be either a laminated composite body or of integral construction.