How to choose the correct diameter of forged steel valves
Nov 15, 2018
The flow path area and flow rate of a forged steel valve are directly related to the flow velocity, and the flow velocity and flow rate are two quantities that are interdependent. When the flow rate is constant, the flow path area can be smaller if the flow velocity is large; the flow path area can be larger if the flow velocity is small. The flow path area is large as the flow velocity is small. On the contrary, the flow path area is small when the flow velocity is large. The flow velocity of the medium is large, and the diameter of the forged steel valve can be smaller, but attention should be paid to the problem of resistance and static electricity. For those media with viscosity or flammability, a small forged steel valve with a small flow path is used.
Pipeline flow is basically determinable, but the flow rate is determined by the experience of the engineer. The flow velocity of each medium will also have a detailed table description. The flow rate and flow velocity can be used to calculate the diameter of the valve to be used. If the forged steel valves have the same diameter, then the structural types are different and the resistance of the fluid is different. Under the same environment, the greater the resistance of the valve body, the smaller the flow rate of the fluid through the forged steel valve; the smaller the resistance of the forged steel valve, and the greater the flow rate of the fluid through the forged steel valve.
Among all kinds of forged steel valves, the resistance of forged steel gate valves is relatively small, only between 0.1 and 1.5. Of course, if the diameter of the forged steel gate valve is relatively large, the resistance is between 0.2 and 0.5. The trapped gate valve has a relatively large resistance. The resistance of the forged steel globe valve will be larger than the gate valve, generally between 4 and 7. The resistance of the Y-type globe valve is smaller, between 1.5 and 2. Forged steel globe valves have the highest resistance and can sometimes reach 8. The resistance of the forged steel check valve is determined according to different structures: the swing check valve is usually 0.8~2, the highest value of the lift check valve is 12. The ball valve has the smallest drag coefficient, which is about 0.1. The resistance coefficients of these forged steel valves are all upgraded when the valve is fully open.
The selection of the forged steel valve's diameter also takes into account the accuracy and dimensional deviation of the valve production. When selecting the valve diameter, one should pay attention to the margin for the diameter, generally around 20%.
All of the above can be summarized as the flow rate and the flow velocity of the valve mainly depend on the diameter of the valve. The structural type of the valve is related to the resistance of the medium. At the same time, it is related to the pressure, temperature and medium characteristics of the valve.
Dervos Forge is a world-class Forge Valve Manufacturer Supplier & Exporter, offering Ball Valve, Check Valve, Gate Valve, Globe Valve in various froged steel materials, sizes, standards and types. Our stable support comes from our skilled workers. Owing to their diligence, our workshop can always fulfill the production on time and keep quality good.