An O-ring seal system for pipe flanges having a backing ring, an O-ring seal positioned within the backing ring, and a vacuum ring positioned within the O-ring seal. The backing ring and the vacuum ring form a rigid base against which mating flanges on pipes can be bolted together, thereby preventing bending of the mating flanges and permitting flange bolts to be torqued to their full tensile load limit without damage to the mating flanges. The O-ring seal system is constructed so that the O-ring seal is retained between the mating flanges without the need to position the O-ring seal in a groove in one of the mating flanges. Bending of the flanges is minimized since the flanges are clamped against the backing ring, minimizing stresses due to bending, thereby extending the service life of the flanges.

A drain coupler includes a drain coupler body having a lower opening and an upper opening. A pliable seal is carried by or adjacent the upper opening, the pliable seal operable to form a water-tight seal about an exterior of a metallic throat section of a drain. Coupler engagement structure is carried by the drain coupler adjacent the upper opening of the drain coupler body. Cap engagement structure is carried by a cap. The cap engagement structure and the coupler engagement structure cooperatively enable removable engagement of the cap over the upper opening of the drain coupler body to temporarily cover the upper opening of the drain coupler. The cap is removable to allow insertion of the metallic throat section in the pliable seal.

A drain coupler includes a drain coupler body having a lower opening and an upper opening. A pliable seal is carried by or adjacent the upper opening, the pliable seal operable to form a water-tight seal about an exterior of a metallic throat section of a drain. Coupler engagement structure is carried by the drain coupler adjacent the upper opening of the drain coupler body. Cap engagement structure is carried by a cap. The cap engagement structure and the coupler engagement structure cooperatively enable removable engagement of the cap over the upper opening of the drain coupler body to temporarily cover the upper opening of the drain coupler. The cap is removable to allow insertion of the metallic throat section in the pliable seal.

An integrated block 1 serving as a fluid device includes: a flow port 13 open to form one end of a passage P; an annular groove 14 arranged along an outer circumferential edge of the flow port 13, the annular groove 14 being open so as to insert the gasket 2 therein; a first tapered portion 17 arranged on a radially-inner side interior wall 14b of the annular groove 14 and sloped radially outward from an open end of the annular groove 14 in a depth direction of the annular groove 14; and a guide 18 arranged on a radially-outer side interior wall 14a of the annular groove 14, extending throughout a predetermined range D from the open end of the annular groove 14 in the depth direction, and having a larger diameter than an outer circumferential surface 22a of a second sealing portion 22 of the gasket 2.

An integrated block 1 serving as a fluid device includes: a flow port 13 open to form one end of a passage P; an annular groove 14 arranged along an outer circumferential edge of the flow port 13, the annular groove 14 being open so as to insert the gasket 2 therein; a first tapered portion 17 arranged on a radially-inner side interior wall 14b of the annular groove 14 and sloped radially outward from an open end of the annular groove 14 in a depth direction of the annular groove 14; and a guide 18 arranged on a radially-outer side interior wall 14a of the annular groove 14, extending throughout a predetermined range D from the open end of the annular groove 14 in the depth direction, and having a larger diameter than an outer circumferential surface 22a of a second sealing portion 22 of the gasket 2.

A hose assembly includes a fitting including a fitting end received in a shell. A sealing element is located at a junction between the fitting and the shell. The first fitting end has a nipple and the shell has an angled end that define a sealing space, and the sealing element is positioned within the sealing space. External pressure at the junction compresses the sealing element within the sealing space to form an energized seal. The shell may include a first shell end and a second shell end, the fitting end of the fitting being received within the first shell end of the shell. The shell my include a plurality of barbs that extend radially inward from an inner diameter of the shell that can grip into a hose, and a barb located closest to the shell end extends radially inward a smaller distance than other barbs to provide a barrier against ingression of contaminants.

A hose assembly includes a fitting including a fitting end received in a shell. A sealing element is located at a junction between the fitting and the shell. The first fitting end has a nipple and the shell has an angled end that define a sealing space, and the sealing element is positioned within the sealing space. External pressure at the junction compresses the sealing element within the sealing space to form an energized seal. The shell may include a first shell end and a second shell end, the fitting end of the fitting being received within the first shell end of the shell. The shell my include a plurality of barbs that extend radially inward from an inner diameter of the shell that can grip into a hose, and a barb located closest to the shell end extends radially inward a smaller distance than other barbs to provide a barrier against ingression of contaminants.

An annular gasket for use between facing flanges of two flow conduit sections, the gasket including an annular gasket substrate made of polytetrafluoroethylene and having a first face opposite a second face. The first face includes a plurality of first serrations wherein the plurality of first serrations includes a plurality of first grooves and a plurality of first peaks, and the second face includes a plurality of second serrations wherein the plurality of second serrations includes a plurality of second grooves and a plurality of second peaks. The plurality of first peaks is aligned with the plurality of second peaks. The plurality of first peaks and the plurality of second peaks are compressible to a substantially flat surface when the conduit sections are joined together in a bolted configuration. An outer guide ring may be positioned exteriorly to the annular gasket substrate.

An annular gasket for use between facing flanges of two flow conduit sections, the gasket including an annular gasket substrate made of polytetrafluoroethylene and having a first face opposite a second face. The first face includes a plurality of first serrations wherein the plurality of first serrations includes a plurality of first grooves and a plurality of first peaks, and the second face includes a plurality of second serrations wherein the plurality of second serrations includes a plurality of second grooves and a plurality of second peaks. The plurality of first peaks is aligned with the plurality of second peaks. The plurality of first peaks and the plurality of second peaks are compressible to a substantially flat surface when the conduit sections are joined together in a bolted configuration. An outer guide ring may be positioned exteriorly to the annular gasket substrate.

A coupling includes an engagement face included in an engagement hook which is set at an angle in a range where the engagement face is still inclined at a positive angle, which is maintained when the coupling and a counterpart coupling are in a coupling state, even if a fluid leaks as a result of opening a sealing portion of the couplings, at a state where the coupling state is maintained, or even if a hose or the like fitted to the coupling bursts when high pressure is applied to the coupling, the hose, etc., while in use.