What is the difference between the installation and function of a butterfly valve and butterfly valve?
Therefore, the fully open position of the valve is determined by the position of the gate. Some gate valve, stem nut is located on the gate, the handwheel rotates to drive the stem to rotate, and make the gate lift, this kind of valve is called rotary bar gate valve, or call dark rod gate valve. The type of gate width, sealing surface configuration can be divided into wedge gate valve and parallel gate valve, wedge gate type valve can be divided into: single gate type, dual gate plate and the flexible gate type; parallel gate type valve can be divided into single and dual gate gate plate. According to the thread position of the valve stem, can be divided into two kinds of open rod gate valve and dark rod gate valve. Valve installation and maintenance should pay attention to the following: hand wheel, handle and transmission mechanism are not allowed for lifting, and is strictly prohibited. Double gate valve should be installed vertically, that is, the valve stem is in a vertical position, and the handwheel is at the top. The gate valve with bypass valve shall be opened before opening to balance the pressure difference between inlet and outlet and reduce the opening force. The gate valve with drive mechanism is installed according to the instruction of the product instruction. If the valve is constantly switched on, lubricate it at least once a month. The valve has the advantages of small fluid resistance, the sealing surface by the erosion of small and medium Chong brush. Opening and closing is more labor-saving. Medium flow direction is unrestricted, no disturbance, no pressure reduction. The utility model has the advantages of simple shape, short structural length, good manufacturing technique and wide application range. Valve faults between the sealing surface can lead to erosion and abrasion, maintenance more difficult. Larger size, open need a certain space, long opening and closing time. Complex structure.
The principle of the valve gate valve is open and close cases, RAM direction of motion perpendicular to the direction of the fluid, valve can only be fully open and fully closed, can not be adjusted and the throttle. Gate has two sealing surface, the most commonly used mode gate valve of the two sealing surface forming wedge, wedge angle with valve parameters vary, usually 50, medium temperature is not high when 2 degrees 52. 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. Gate valve with the stem along with a straight line of motion, called the lift rod gate valve is also known as the bar gate valve. Usually there is a trapezoidal thread on the lifter. The rotating motion is changed into a straight line through the nut at the top of the valve and the guide groove on the valve body. That is to say, the operating torque is changed into the operating thrust. When opening the valve, when the gate lift height is equal to 1:1 times of the valve path, the passage of the fluid is completely unblocked, but at run time, this position is unable to monitor. In actual use, the top of the stem is used as a sign, i.e., the open position, as its fully open position.Temperature changes appear to consider locking phenomenon, usually open to the vertex position, and then rewind 1/2 1 circle, as a fully open valve position.
