Abstract: Provided is a mechanical seal that ensures the flow rate of a cooling fluid, which is necessary to cool a slide seal surface, and that can prevent erosion from occurring. In the mechanical seal, the ratio between the depth and the width of each groove of a partial impeller is 2.0-5.0; the ratio of the distance between the grooves of the partial impeller to the width of a weir of a casing is 0.5-3.1; the ratio of the total length of the widths of the grooves of the partial impeller to the total length of the peripheral surface of the partial impeller, in which the grooves are formed, is 0.28-0.8; or the ratio of the length of the projected portion of the tip of each groove of the partial impeller to the width of a cooling liquid discharging groove of the casing is greater than 0 and less than or equal to 0.65.

Abstract: A method of producing a diaphragm damper 1 having a high pressure chamber 3 comprised of two diaphragms 2 with flanges 6 welded together and charged inside with a high pressure gas. The diaphragms 2 are made of magnetically attractable thin metal sheets. A pair of jigs 30, 40 provided to face each other inside the pressure vessel 20 hold the diaphragms 2 by magnetic force. The pressure vessel 20 is sealed and evacuated, then the pressure vessel 20 is charged and pressurized by a mixed gas including helium. After this, the pair of jigs 30, 40 are made to approach each other to make the flanges 6 of the pair of diaphragms 2 come into close contact. Inside the pressure vessel 20, the jigs 30, 40 are simultaneously rotated to rotate the pair of diaphragms 2 and a laser beam is fired at the flanges 6 of the diaphragms 2 to weld the flanges 6 over their entire circumferences.

Abstract: Provided is a mechanical seal that ensures the flow rate of a cooling fluid, which is necessary to cool a slide seal surface, and that can prevent erosion from occurring. In the mechanical seal, the ratio between the depth and the width of each groove of a partial impeller is 2.0-5.0; the ratio of the distance between the grooves of the partial impeller to the width of a weir of a casing is 0.5-3.1; the ratio of the total length of the widths of the grooves of the partial impeller to the total length of the peripheral surface of the partial impeller, in which the grooves are formed, is 0.28-0.8; or the ratio of the length of the projected portion of the tip of each groove of the partial impeller to the width of a cooling liquid discharging groove of the casing is greater than 0 and less than or equal to 0.65.

Abstract: A method of producing a diaphragm damper 1 having a high pressure chamber 3 comprised of two diaphragms 2 with flanges 6 welded together and charged inside with a high pressure gas. The diaphragms 2 are made of magnetically attractable thin metal sheets. A pair of jigs 30, 40 provided to face each other inside the pressure vessel 20 hold the diaphragms 2 by magnetic force. The pressure vessel 20 is sealed and evacuated, then the pressure vessel 20 is charged and pressurized by a mixed gas including helium. After this, the pair of jigs 30, 40 are made to approach each other to make the flanges 6 of the pair of diaphragms 2 come into close contact. Inside the pressure vessel 20, the jigs 30, 40 are simultaneously rotated to rotate the pair of diaphragms 2 and a laser beam is fired at the flanges 6 of the diaphragms 2 to weld the flanges 6 over their entire circumferences.

Abstract: A pipe joint 1 comprises a fitting 10 connected with a hose 2, a flange 20 pressingly holding the fitting 10 inserted into a through hole 21 toward a block 3, a bolt 30 for fixing tightly the flange 20 to the block 3, a metal seal 40 having “C” cross section so as to seal a joined portion of a communication passage 11 and a connection opening 3a externally, and a first and a second O-rings 50, 60 so as to seal a contact portion of the fitting 10 and the block 3. A projecting portion 24 is formed on a lower face 23 of the flange 20, the projection portion 24 is formed at an area opposite to an area where the insertion hole 21 is formed with respect to a center axis of the through hole 21, the project portion 24 projects from other portion of the flange towards the block 3. A tip of the fitting 10 inserted into the through hole 21 projects towards the block 3 from the lower face 23 of the flange 20.

Abstract: A pipe joint 1 comprises a fitting 10 connected with a hose 2, a flange 20 pressingly holding the fitting 10 inserted into a through hole 21 toward a block 3, a bolt 30 for fixing tightly the flange 20 to the block 3, a metal seal 40 having “C” cross section so as to seal a joined portion of a communication passage 11 and a connection opening 3a externally, and a first and a second O-rings 50, 60 so as to seal a contact portion of the fitting 10 and the block 3. A projecting portion 24 is formed on a lower face 23 of the flange 20, the projection portion 24 is formed at an area opposite to an area where the insertion hole 21 is formed with respect to a center axis of the through hole 21, the project portion 24 projects from other portion of the flange towards the block 3. A tip of the fitting 10 inserted into the through hole 21 projects towards the block 3 from the lower face 23 of the flange 20.

Abstract: A method of producing a diaphragm damper 1 having a high pressure chamber 3 comprised of two diaphragms 2 with flanges 6 welded together and charged inside with a high pressure gas. The diaphragms 2 are made of magnetically attractable thin metal sheets. A pair of jigs 30, 40 provided to face each other inside the pressure vessel 20 hold the diaphragms 2 by magnetic force. The pressure vessel 20 is sealed and evacuated, then the pressure vessel 20 is charged and pressurized by a mixed gas including helium. After this, the pair of jigs 30, 40 are made to approach each other to make the flanges 6 of the pair of diaphragms 2 come into close contact. Inside the pressure vessel 20, the jigs 30, 40 are simultaneously rotated to rotate the pair of diaphragms 2 and a laser beam is fired at the flanges 6 of the diaphragms 2 to weld the flanges 6 over their entire circumferences.