What are the differences between the gate valve and the cut-off valve?
Is the gate valve opening and closing parts, RAM direction of motion perpendicular to the direction of the fluid, valve can only be fully open and fully closed, is not suitable for regulation and throttle. The gate has two sealing surfaces. The two sealing surfaces of the most commonly used wedge gate valves form a wedge. The wedge angle varies with valve parameters, usually 5o. Wedge gate valve can be made into a whole, called the rigid gate; can also be made to produce micro deformation of ram, in order to improve its process of deviation, make up the sealing surface angle in the process, the gate is called the flexible gate. Valve closed, the sealing surface can only rely on medium pressure to seal, that is to rely on medium pressure to the gate sealing surface pressure to the other side of the seat to ensure the sealing surface seal, which is self sealing. Most of the valve is forced seal, that is, when the valve closes, to rely on external force to force the gate to the seat, in order to ensure the sealing surface sealing.A stop valve is a valve that closes the valve and moves along the center line of the valve seat. According to this form of valve movement, the valve seat opening change is proportional to the valve stroke. Because of the valve stem to open or close the trip is relatively short, but very reliable cut off function, and because changes in the valve seat and the valve stroke is proportional, is very suitable for flow regulation. As a result, this type of valve is ideal for use as a shut-off or regulator and throttling
3, the valve is used in the system is relatively large, to close the gate off system; and the valve is used in the system is relatively small, and to adjust the flow quantity of the system, can not be closed gate and globe valves of different specifications for a variety of occasions, such as the valve rod the dark bar valve, gate valve, wedge gate valve, single valve, multi valve valve body structure is different, large volume. Generally large and nominal caliber DN50 mostly with gate valve, especially industrial high temperature, high pressure and other occasions.4, the cut-off valve is able to stop and adjust the flow, small footprint, small size, generally less than the nominal diameter, DN50 occasions use it. Two can be closed, in the flow of linear requirements are not high, you can adjust the flow. Just because of its structural characteristics of the valve to make its flow resistance, so there is a demand for throttling with a little more than the gate valve. In addition, the cut-off valve, whether it is a formal or reverse installed, in the opening and closing process, there is always a very difficult, and therefore can not do a great deal, or it is not easy to open and close. In addition, the sealing valve has the characteristics of one-way sealing effect, so that the utility model can prevent the working substance from flowing upstream
The operating principle is different. The stop valve is an upward stem type, and the handwheel rotates and rises with the stem. Valve is hand wheel rotation, stem upward movement. Flow is not the same, the gate valve requires full open, the cut-off valve is not the same. The gate valve has no inlet and outlet direction requirements, and the cut-off valve has the required inlet and outletAt the same time, usually with the cut-off valve instead of gate valve, but the valve can also be used instead of cut-off valve. Valve sealing performance better, but the size is generally not large, the size of the gate valve can be done great.The main difference between them lies in:1, different structure, gate valve structure is more complex than the height, larger size, from the appearance point of view than the cut-off gate valve is short and high, especially the gate height space needs a higher open bar, the selection in the installation space under the condition of limited attention to.2, sealing surface, valve in the opening and closing valve and the valve seat surface always contact and friction between the sealing surface, and thus easy to wear, especially in close off the valve when the valve before and after the great pressure, sealing surface wear is more serious. And the valve once the valve is in open condition, it's seat and disc sealing surface between, not in contact,
