Abstract: A sealing microsawtooth ring joint, made between a toothed seating surface and a full plain seated surface by a microsawtooth ring with its tooth crest on the seating surface being a cutting edge whose corner or whose crest angle is about 90°˜120°, with its tooth height Zt being about 10˜20 times the roughness Ra of the seated surface, and with the ratio of its tooth pitch Xs to its tooth height Zt being 20˜500 to ensure that the tight joint has a microcosmic line contact followed by a surface contact or to ensure that the tight joint has both such a line contact as to be able to provide a necessary seating stress locally and such a surface contact as to be able to protect the line contact from being excessively pressed to get blunt or disappeared, can be used either as a pressure-tight joint or as a self-energizing tight joint of any too surfaces such as flats to flats, cones to cones or spheres, spheres to spheres or cones etc.

Abstract: A sealing microsawtooth ring joint, made between a toothed seating surface and a full plain seated surface by a microsawtooth ring with its tooth crest on the seating surface being a cutting edge whose corner or whose crest angle is about 90°˜120°, with its tooth height Zt being about 10˜20 times the roughness Ra of the seated surface, and with the ratio of its tooth pitch Xs to its tooth height Zt being 20˜500 to ensure that the tight joint has a microcosmic line contact followed by a surface contact or to ensure that the tight joint has both such a line contact as to be able to provide a necessary seating stress locally and such a surface contact as to be able to protect the line contact from being excessively pressed to get blunt or disappeared, can be used either as a pressure-tight joint or as a self-energizing tight joint of any too surfaces such as flats to flats, cones to cones or spheres, spheres to spheres or cones etc.

Abstract: A sealing microsawtooth ring joint, made between a toothed seating surface and a full plain seated surface by a microsawtooth ring with its tooth crest on the seating surface being a cutting edge whose corner or whose crest angle is about 90°˜120°, with its tooth height Zt being about 10˜20 times the roughness Ra of the seated surface, and with the ratio of its tooth pitch Xs to its tooth height Zt being 20˜500 to ensure that the tight joint has a microcosmic line contact followed by a surface contact or to ensure that the tight joint has both such a line contact as to be able to provide a necessary seating stress locally and such a surface contact as to be able to protect the line contact from being excessively pressed to get blunt or disappeared, can be used either as a pressure-tight joint or as a self-energizing tight joint of any two surfaces such as flats to flats, cones to cones or spheres, spheres to spheres or cones etc.

Abstract: Any stem seal using either a triangle-sectional bushing or ring as stem cylinder seals or a ball wedge/spherical socket mating arrangement as stem shoulder seals can individually withstand the same pressure as the burst pressure of bodies without failure. The sectional triangle of the triangle-sectional bushing or ring is truncated to provide a wearing and compressing allowance for the bushing or ring, and so will be again a full triangle or an untruncated triangle when the bushing or ring is fully worn. The ball wedge/spherical socket mating is a mating which uses ball wedges as a stop shoulder of stems and the spherical socket as a stop socket at stem exits.

Abstract: A stem shoulder seal with double rings is composed of a sealing ring, a clamping ring and a spherical or conical stem shoulder, and the sealing ring is of a self-energized seal designed to its ultimate allowable strength and automatically free of any load beyond its ultimate strength. An assembly of independent dual stem seals, consisting of a stem shoulder seal with double rings, a stem cylinder seal with triangular sections and an isolating mating, can ensure that a stem has three seals which get well seated automatically at the same time to bear an identical ultimate medium pressure independently or without any mutual interference in service when assembled to the extent that the stem operating torque is just definitely increased, thereby ensuring that a stem sealing has a triple safety.

Abstract: A gland seal designed according to the joint's factors m and y and the seal-designing rule refined from ASME Code to result in its minimum necessary seating stress y at no fluid pressure being so small to be ignorable that its sealing maintenance factor or disturbance resistance index m, equal to the joint's sealing actuation force divided by the joint's unseating actuation force, can be used to indicate its sealing safety at a fluid pressure: when m=1, its sealing actuation force equals its unseating actuation force or equals its “seating area×fluid pressure” and so it can be kept leak-free under no upset disturbance condition and may leak at an upset moment, and when m>1, it can be resistant to an upset disturbance and be the greater, the more resistant. The factor m for a self-energizing tight joint is equal to its fluid's sealing actuation area divided by its fluid's unseating actuation area.

Abstract: A trapezoid-sectional annular sealing arrangement, including a trapezoid-sectional annular cavity and gasket or packing used to realize the sealing connection of two fluid-containing members connected by fastening threads or bolts, wherein the said annular gasket or packing is enclosed in the said annular cavity formed by the said two fluid-containing members as joined together by fastening threads or bolts, the said trapezoid is disposed to converge radially and inward, the annular gasket or packing has a sectional area slightly bigger than the sectional area of the annular cavity, and the annular cavity is preferably designed to completely sink into one face of the two end faces to be joined. The sectional area and gyro-radius of the annular gasket with a material thermal expansion coefficient different from the annular cavity will either increase or decrease in response to temperature changes at the same time relative to the annular cavity to enhance or retain the original sealing connection.

Abstract: A stem seal used either a triangle-sectional bushing as stem cylinder seals or a ball wedge/spherical seat mating as stem shoulder seals can individually withstand the same pressure as the burst pressure of bodies without failure. The sectional triangle of the triangle-sectional bushing is truncated to provide a wearing and compressing allowance for the bushing, but will be again a full triangle or an untruncated triangle when the bushing is fully worn. The ball wedge/spherical seat mating is a mating which uses ball wedges as a stop shoulder of stems and the spherical seat as a stop seat at stem exits.