Valve technology advantages and disadvantages compared

Valve is the control unit in fluid conveying system, with a cut-off, regulation, guide, to prevent the reverse flow, voltage regulator, the leakage of the shunt or overflow, and other functions. The valve is also commonly used in chemical instrumentation, understand the characteristics of the valve, also helps to safety production. Valve is the control unit in fluid conveying system, with a cut-off, regulation, guide, to prevent the reverse flow, voltage regulator, the leakage of the shunt or overflow, and other functions. Used for fluid flow control system of the valve, from the most simple cut-off valve to extremely complex automatic control system used in all kinds of valves, its quite a wide varieties and specifications. The valve can be used to control air, water, steam, all kinds of corrosive medium, mud, oil, liquid metal and radioactive medium, etc. All types of fluid flow. Valve according to the material is divided into iron valves, cast steel valves, stainless steel valves, 201, 304, 316, etc. ) Molybdenum chrome vanadium steel, chrome molybdenum steel valves valve, dual phase steel valves, plastic valves, such as non-standard custom-made valve material. Gate valve gate valve is closed ( Ram) Along the channel axis vertical direction valve, mainly for cut off the medium in the pipe on the road, that is fully open or close. In general, gate valves cannot be used as a flow adjustment. It can apply pressure at low temperature can also be applied to high temperature and high pressure, and according to the different material of the valve. But the gate is generally not used for conveying slurry medium in pipeline. Gate valves according to the position on the valve stem threads are divided into the Ming bar type and dark bar type two kinds. From the structure characteristics of ram and can be divided into two categories, wedge, the parallel type. Wedge gate valve sealing surface and the vertical center into a point of view, and mostly made single ram. Parallel gate valve sealing surface parallel to the vertical center, and mostly made double ram. Gate valve sealing performance is good cut-off valve, fluid resistance small, has a certain regulation performance, Ming rod can be adjusted according to the valve stem lifting height is closing, the disadvantage is that structure a globe valve is complex, easy to wear and tear on sealing surface, not easy to repair. Gate except the applicable to steam, oil, etc, also suitable for granular solid meter high viscosity medium, and is suitable for the exhaust valve and valve of low vacuum system. Advantages: (1) fluid resistance small; (2) the opening and closing torque smaller; (3) can be used in the medium flow in two directions of ring network management way, that is to say, the flow of medium is not restricted; (4) is wide open, the sealing surface erosion by working medium is smaller than globe valves; (5) the form structure is relatively simple, manufacture good manufacturability; 6 structure length is shorter. Disadvantages: (1) overall dimensions and open height is bigger, the required installation space is larger; (2) in the process of opening and closing, the sealing surface relative to the friction, friction losses, even at high temperature easy to cause scratches phenomenon; (3) general gate valve has two seal face, adds some difficulties to machining, grinding and maintenance; (4) opening and closing time is long.