How to analyze the performance of different structure of valve:gate valve is a valve is widely used in the pipeline,mainly to connect and disconnect the media.Not for regulating the flow of media,but to determine the size of the flow according to the level of stem down(such as fire elastic sealing gate valve with scale).Compared to other gate valve for pressure,temperature,diameter and other requirements of the applicable scope is wide.
According to the different internal structure can be divided into:wedge type single gate plate,elastic plate type,double gate plate,parallel gate type.
According to the different stem support can be divided into:the bright pole gate valve and the dark bar gate valve.
The main advantages of the valve are:
1,the valve fluid resistance is small,because the valve body is straight,medium flow does not change direction,and therefore more than other valve flow resistance to be small.
2,the sealing performance is better than the cut-off valve,open and close also compared with the cut-off valve.
3,wide applicable range,except for the steam,oil and other media,is also suitable for containing granular solids and the medium viscosity is bigger,also suitable for low vacuum system and vent valve of valve to use.
4,the valve is a dual flow of the valve,not subject to the flow of media restrictions,and therefore apply to the media may change the flow direction of the pipeline,but also easy to install.
The main performance of the valve defects are:
1,the size of the design is high,from a long time to open the valve plate needs to be raised to the upper part of the valve cavity,and the valve plate is closed down and all fall into the valve seat,so the valve plate open and close the trip,a long time.
2,due to the valve plate and valve seat of the two sealing surface in the process of opening and closing friction,so the sealing surface is easy to scratch,sealing performance and service life are affected,and is not easy to repair.
Performance comparison of several kinds of gate valves with different structures:
(1)wedge gate valve
A,the structure is simpler than the elastic gate valve
B,at a higher temperature,the sealing performance is not as good as the elastic gate valve or double disc valve.
C,high temperature medium suitable for easy coking.