Selection Principle Of Globe Valve
The globe valve means the closing member closing the valve moving along the center line of the valve seat. In general, according to this type of movement of the valve flap, the valve seat port is in a positive proportional relationship with the valve flap stroke when the valve stem opening or closing stroke of the shut-off valve is relatively short and has a very reliable cut-off function, And the change of the valve seat port is in a positive ratio relation with the stroke of the valve flap, and is very suitable for regulating the flow. Therefore, the shut-off valve is well-suited for use as a cut-off or adjustment and for throttling.
The principle of selection of stop valve is as follows:
1. Globe valve should be selected on the pipeline or device of high temperature and high pressure medium. Such as thermal power plants, nuclear power plants, petrochemical systems on the high temperature pipeline.
2. On a pipeline where the flow resistance is not strictly required, i.e. where little consideration is given to pressure loss.
3. Small valves can be needle type, instrument valve, sampling valve, pressure gauge valve, etc.
4. There are flow regulation or pressure regulation, but the adjustment accuracy requirements are not high, and the diameter of the pipeline is relatively small, such as nominal diameter ≤50mm pipeline, it is appropriate to choose.
5. The high pressure angle globe valve or high pressure angle throttle valve of nominal pressure pn160 nominal pressure 16mpa or pn320 nominal pressure 32mpa should be selected for small and large chemical fertilizers in synthetic industrial production.
6. in the desilication workshop of alumina Bayer process, the direct flow globe valve or DC throttle valve of cemented carbide seal pair is easy to be selected on the line with easy coke, the valve body is separated, the valve seat can be removed, and the cemented carbide seal pair is used for direct flow globe valve or DC throttle valve.
7. The pipeline with smaller nominal diameter on water supply and heat supply project in urban construction can be selected as cut-off, balance valve or valve, such as nominal diameter, for example, with nominal diameter less than 150mm, and the most obvious advantage is that during opening and closing, Since the friction between the valve flap and the sealing surface of the valve body is smaller than the gate valve, the wear resistance and opening height are generally only 1/4 of the diameter of the valve seat channel. And therefore, only one sealing surface is formed on the valve body and the valve clack than the gate valve, so the manufacturing manufacturability is good, and the maintenance is convenient.