Location: The knowledge and advantages of the drainage gate valves
Author: admin Time: 2011/12/12 23:06:30 Hits:
China valve opening and closing of the drainage gate valves) is a ram, the movement direction of the disc and fluid in vertical direction, gate valve can only be fully open and seated, not to adjust and throttling. Disc has two seal face, the most common mode of the valve gate two seal face form, wedge Angle valve wedge with different parameters, usually 50, the temperature of the medium is not high as 2 ° 52. Wedge type the wedge disc of the gate valves can be made into a whole, called the rigid disc; Can also make it can produce a trace of the deformation of the ram, to improve its technology, make up for seal face Angle in processing produces in the process of the deviation, the disc called elastic disc.
Gate valves closing, seal face can only rely on medium pressure to seal, which rely on medium pressure will sealing face of the gate to the pressure in the other side of the seat to ensure the sealing seal, this is the seal. Most of the gate is to use force sealed, namely the valve closed when, want to rely on outside force forced the disc pressure to the seat, to ensure the sealing seal face.
The wedge disc of the gate valves with the stem be linear motion, that lift stem gate valves also called rising stem valves. Usually in the lift stem has the trapezoidal thread, through the top of the valve body nuts and the guide groove, will the rotary motion into a linear motion, is also to operation torque thrust into operation.
Open valve, when the disc is equal to the hoisting height valve size 1:1 times, fluid channels completely clear, but in operation, this position is unable to monitor. In practice, is based on the stem vertex as a symbol of, that is still open position, as it's in full open position. For considering temperature changes occur locked phenomenon, normally in the open position on it to the top, then the back to 1/2-1 lap, as a full open the valve position. Therefore, the valve in full open position, according to the position of the disc (i.e. travel > to determine.
Some gate valve, the valve stem nut in the gate, and turn the handwheel drive stem rotation, and make the disc to ascend, the valve rod rotation is called a gate or call dark bar gate valves.
Gate valves has the following advantages:
Fluid resistance small, sealing surface of the medium by Chong brush and erosion small. Open and close more effort. The flow direction of medium not restricted, not, not reduce the pressure turbulence. Simple form, structure length short, manufacturing technology, application scope.
The weaknesses of the gate valves are as follows:
Seal face between easy cause erosion and scratches, maintenance is hard. Overall size is larger, open needs certain space, open and close time long. Structure is more complex.
The types of rich gate, according to seal face configuration can be divided into wedge type disc type gate valves and parallel disc type gate valves, wedge type disc type gate valves can be divided single poly line type, double disc type and elastic disc type; Parallel disc type gate valves can be divided into the single disc type and double disc type. According to the stem threads positions, can be divided into rising stem valves and dark bar gate valves two kinds.
Gate valves installation and maintenance should notice the following matters:
The handwheel, the handle and transmission mechanism for are not allowed to use it, and it is strictly prohibited to collide. Double disc gate valves should be installed vertically (namely the stem is in the vertical position, the handwheel on top. With bypass valve gate valves should be in the open before the first open the valve to balance the import and export (differential pressure and reduce open force. Take transmission's gate, according to the provisions of the product specifications installation. China valve remind, if the valve often switches use, at least once a month lubrication.
Gate valves closing, seal face can only rely on medium pressure to seal, which rely on medium pressure will sealing face of the gate to the pressure in the other side of the seat to ensure the sealing seal, this is the seal. Most of the gate is to use force sealed, namely the valve closed when, want to rely on outside force forced the disc pressure to the seat, to ensure the sealing seal face.
The wedge disc of the gate valves with the stem be linear motion, that lift stem gate valves also called rising stem valves. Usually in the lift stem has the trapezoidal thread, through the top of the valve body nuts and the guide groove, will the rotary motion into a linear motion, is also to operation torque thrust into operation.
Open valve, when the disc is equal to the hoisting height valve size 1:1 times, fluid channels completely clear, but in operation, this position is unable to monitor. In practice, is based on the stem vertex as a symbol of, that is still open position, as it's in full open position. For considering temperature changes occur locked phenomenon, normally in the open position on it to the top, then the back to 1/2-1 lap, as a full open the valve position. Therefore, the valve in full open position, according to the position of the disc (i.e. travel > to determine.
Some gate valve, the valve stem nut in the gate, and turn the handwheel drive stem rotation, and make the disc to ascend, the valve rod rotation is called a gate or call dark bar gate valves.
Gate valves has the following advantages:
Fluid resistance small, sealing surface of the medium by Chong brush and erosion small. Open and close more effort. The flow direction of medium not restricted, not, not reduce the pressure turbulence. Simple form, structure length short, manufacturing technology, application scope.
The weaknesses of the gate valves are as follows:
Seal face between easy cause erosion and scratches, maintenance is hard. Overall size is larger, open needs certain space, open and close time long. Structure is more complex.
The types of rich gate, according to seal face configuration can be divided into wedge type disc type gate valves and parallel disc type gate valves, wedge type disc type gate valves can be divided single poly line type, double disc type and elastic disc type; Parallel disc type gate valves can be divided into the single disc type and double disc type. According to the stem threads positions, can be divided into rising stem valves and dark bar gate valves two kinds.
Gate valves installation and maintenance should notice the following matters:
The handwheel, the handle and transmission mechanism for are not allowed to use it, and it is strictly prohibited to collide. Double disc gate valves should be installed vertically (namely the stem is in the vertical position, the handwheel on top. With bypass valve gate valves should be in the open before the first open the valve to balance the import and export (differential pressure and reduce open force. Take transmission's gate, according to the provisions of the product specifications installation. China valve remind, if the valve often switches use, at least once a month lubrication.