Various pipe accessories and fittings such as pipes and valves together constitute the water supply pipe network system. In the water supply pipe network system, because the data such as water volume, water speed, water pressure and other data in the pipe network need to be adjusted in time, and at the same time, there may be problems with the water supply system at any time, and the work needs to be repaired or maintained. A large number of valve opening and closing operations, these operations are very small behaviors, but because of the need to keep repeating operations, after a certain number of operations, the water supply network valve will be damaged, thus losing its function. Function. The service life of the valve and its quality are related to whether the pipe network can be used for a long enough time. Valves play an important role in the pipeline network, and relevant departments must pay attention to it.
Introduction of the valve
The main basic function of the valve in the water supply pipe network system is to open and close. This method is used to control the smooth flow and block of the pipeline fluid, and at the same time adjust the flow state of the mass and the pressure of the pipeline. The valve plays a very important role in the water supply network system, it protects the normal operation of the pipeline and related equipment, and has a non-negligible importance to the stability of the system. In actual operation, according to the different operation methods, valves are divided into many kinds, such as: globe valve, ball valve, plug valve and butterfly valve, etc. Different valves are divided into many kinds according to the difference of their structure.
characteristics of the valves
There are many characteristics of the valve. In the water supply network, for the water supply pipeline, it is mainly divided into use characteristics and structural characteristics.
The use characteristics of the valve determine the main function of the valve, and its characteristics also determine the scope of use to some extent, and can only be used within this scope. The characteristics of valve use include: valve category (closed-circuit valve, regulating valve, safety valve, etc.); product type (gate valve, globe valve, butterfly valve, ball valve, etc.); valve main parts (valve body, valve cover, valve stem, valve valve, sealing surface) material; valve transmission mode, etc.
The structural characteristics of the valve are also relatively unique, but it determines some structural characteristics of the valve installation, repair, maintenance and other methods. The structural characteristics include: the structural length and overall height of the valve, the connection form with the pipeline (flange connection, threaded connection, external thread connection, welding end connection, etc.); the form of the sealing surface (insert ring, threaded ring, surfacing welding , spray welding, valve body); valve stem structure (rotating rod, lifting rod), etc.
Valve selection steps
The specific steps for selecting a valve should be to first understand the characteristics of the valve, then master the steps and basis for selecting a valve, and finally determine the valve to be selected according to the principles of valve selection.
The first step should be to understand what the valve needs to do, what it does, where it will be used, and some of the usage and structural properties it needs. When the working conditions of the valve are specifically determined, the pipeline medium controlled by the valve, the pressure of the pipeline and the temperature of the specific work can be determined;
The second step is to determine whether the connection method is flange, thread or welding by querying the information or having mastered the way the valve is connected to the pipeline. These three connection methods are different, and different connection methods will lead to the required valve type. not the same;
The third step is to determine the method of valve operation. The commonly used valve operation methods are manual, electric, pneumatic and electrical linkage methods. These operation methods can be selected according to the specific operating environment;
Fourth, it should be clear what type of substance is running in the pipeline. Different substances require different valve characteristics. The working pressure and temperature required by the substance are different, and the requirements of the valve will also increase, which is not suitable for The valve will bring side effects to the work, affect the progress of the work, and even cause losses;
In the fifth step, according to the results of the above steps, the types of valves required can be determined, which can be roughly divided into different types such as closed-circuit valves, regulating valves, and safety valves;
The sixth step is to determine the parameters of the valve, and use accurate instruments to measure the required geometric parameters of the valve, including data such as structural length, size, and direction.
The seventh step, select the specific valve.
safety of water supply
In the water supply network system, the quality of the valve deserves everyone’s attention. It is the most basic guarantee that the valve does not affect the quality of the delivered water. The place where the valve is in contact with water is mainly the inside of the valve, which is sealed. At present, many valve manufacturers are made of rubber materials. The basic principle of selecting these rubber materials is that they are absolutely harmless to the human body. In the past, manufacturers used painting to solve the problem of rust prevention. However, painting does not guarantee that the valve has no quality problems. Once the paint on the valve is harmful to the human body, such a valve will enter the valve through the transmission of water flow. It will cause great social disasters and even serious situations such as infection with infectious diseases. Therefore, these valve positions that come into contact with water must be painted with natural non-toxic paint that is not harmful to the human body. And it is best to use electrostatic spraying to work. Therefore, in order to ensure the safety of water supply, the relevant valve procurement department must pay attention to these details when selecting and purchasing, and must not be negligent, so as not to cause a huge threat.
tightness of the valves
The way to check whether the valve plays a key role is to test the tightness of the water flow, which is also one of the most basic requirements. In the actual operation process, the staff can use soft sealing, hard sealing and other methods to seal, and the final result of these sealing operations must ensure the tightness of the water flow. In actual water supply enterprises, butterfly valves are usually not used because the characteristics of such butterfly valves cannot be reflected. When replacing the coil, it is necessary to open the pipeline of the valve. In this way, the sealing performance is greatly doubted, and the effect after the replacement cannot be confirmed. Therefore, when selecting the relevant valve, the tightness of the water flow must be considered, and the valve that is most suitable for the situation must be selected according to the actual situation.
Whether the pipeline is smooth or not and whether the medium in the pipeline can pass normally depends on this small valve. However, the selection of the valve should take into account the relevant different situations, and different situations are suitable for different valves. If the valve is arbitrarily selected, it will inevitably lead to The outbreak of other problems will affect the normal operation of the entire system. Therefore, the selection of valves should comprehensively consider various requirements and influencing factors, and select the type of valve that is most suitable for the conditions, which will bring great impact to the operation of the water supply network. Convenience, to achieve effective control of the medium.