Knowledge

Basic requirements of the flexible wedge rising stem gate valve?



The open and close parts of the flexible wedge rising stem gate valve is disc. The direction of movement of the gate is perpendicular to the direction of the flow. The gate valve can only be fully opened and fully closed, and it cannot be adjusted or throttled. The gate has two sealing surfaces. The two sealing surfaces of the most commonly used mode gate valves form wedges, and the wedge angle varies with the valve parameters, typically 50, and 2°52”” when the medium temperature is not high. Wedge gate valve gate can be made into a whole, called the rigid gate; can also be made of a slight deformation of the gate to improve its craft, to make up for the deviation of the sealing surface angle in the process, this kind of brake The board is called a flexible shutter. This type of valve should generally be installed horizontally in the pipeline.

       The elastic seat gate valve is also called a lift rod gate valve (also called a stem gate valve). Trapezoidal threads are usually provided on the lifting rods. The nut on the top of the valve and the guide groove on the valve body convert the rotation into a linear motion, that is, the operating torque becomes the operating thrust. When the valve is opened, when the lifting height of the gate is equal to 1:1 of the valve diameter, the channel of the fluid is completely open, but this position cannot be monitored during operation. In actual use, the vertex of the valve stem is used as a mark, that is, a position that does not move, as its fully open position. In order to consider the phenomenon of lock-up temperature change, usually in the open to the top position, and then back 1/2 -1 turn, as the position of the fully open valve. Therefore, the fully open position of the valve is determined by the position of the gate (ie stroke).

       common enquiries

      1 The specification and type of the flexible valve seated valve should meet the requirements of the pipeline design documents.

      2 The model number of the elastic seat gate valve should be specified according to the national standard numbering requirements. If it is a corporate standard, the description of the model should be specified.

      3 The working pressure of the closed valve of the dark shaft elastic seat is required. ≥ The working pressure of the pipeline is required. Under the premise of not affecting the price, the working pressure of the valve can be greater than the actual working pressure of the pipeline; One side should be able to withstand 1.1 times the valve work pressure without leakage; valve open conditions, the valve body should be able to withstand the requirements of the double valve pressure.

      4 The manufacturing standards for open-rod flexible seated gate valves should state the number of the national standard to which the valve is based. If it is a corporate standard, an enterprise document should be attached to the procurement contract.