The classification is different
Stop valve: 1) Direct-flow stop valve: In direct-flow or Y-shaped stop valve, the flow passage of the valve body is in a diagonal line with the main flow passage, so that the damage degree of the flow state is smaller than that of the conventional stop valve, so the pressure loss through the valve is also corresponding Is too small. 2) Angle type stop valve: In the angle type stop valve, the fluid only needs to change its direction once, so that the pressure drop through this valve is smaller than that of the conventional structure of the stop valve. 3) Plunger type globe valve: This type of globe valve is a variation of the conventional globe valve.
Ball valve: Function classification: 1) Bypass valve: The ball valve is generally opened by static water, so the bypass valve is set to be pressed first, that is, both sides are filled with water. 2) Air valve: when filling with water, the buoy will automatically close the valve when the air is removed; when draining, the buoy will drop by itself when it is used for replenishing air; 3) Pressure relief valve: When opening and closing the valve, remove the pressure water between the valve and the sealing cover to avoid wearing the sealing cover; 4) Drain valve: drain the sewage in the lower part of the ball shell.
The characteristics are different
Stop valve: 1) The structure of the stop valve is simpler than that of the gate valve, and it is more convenient to manufacture and maintain. 2) The sealing surface is not easy to wear and scratch, and the sealing performance is good. There is no relative sliding between the valve disc and the sealing surface of the valve body when opening and closing, so the wear and scratches are not serious, the sealing performance is good, and the service life is long. 3) When opening and closing, the disc stroke is small, so the height of the stop valve is smaller than that of the gate valve, but the structure length is longer than that of the gate valve.
Ball valve: 1) Wear resistance; since the valve core of the hard-sealed ball valve is spray welded with alloy steel, and the sealing ring is welded with alloy steel, the hard-sealed ball valve will not produce too much wear when it is switched on and off. 2) The sealing performance is good; because the sealing of the hard-seal ball valve is manually ground, it can not be used until the valve core and the sealing ring are completely matched. Therefore, its sealing performance is reliable.
The working principle is different
Stop valve: The closing principle of the globe valve is to rely on the pressure of the valve stem to make the sealing surface of the disc and the sealing surface of the valve seat closely fit to prevent the medium from flowing. Our country's valve "Sanhua" once stipulated that the flow direction of the stop valve should be from top to bottom, so there is directionality when installing.
Ball valve: A valve in which the opening and closing part (ball) is driven by the valve stem and rotates around the axis of the ball valve. It can also be used for fluid adjustment and control. Among them, the hard-sealed V-shaped ball valve has a strong shear force between the V-shaped core and the metal seat of the hard alloy surfacing. It is especially suitable for fibers and small solid particles. And other media.