Globe valves are used to cut off the flow of media. Globe valves are suitable for occasions requiring frequent opening. They are most commonly used in chemical production.
The sealing parts of globe valves are discs and seats. In order to close the globe valves tightly, the mating surfaces of the discs and seats should be ground or gasketed, and corrosion-resistant and wear-resistant materials such as bronze and stainless steel can be inlaid on the sealing surfaces. The disc and stem of the globe valve are movably connected to facilitate the disc and stem to closely fit.
The rise and fall of the disc of the globe valve is generally controlled by the stem. The upper part of the stem of the globe valve is the handwheel, and the middle part is the thread and packing sealing section. The function of the packing is to prevent the leakage of the medium inside the valve body along the stem.
The main function of globe valve in chemical pipeline is to cut off or connect the fluid. The regulating flow rate of globe valve is better than that of gate valve. But globe valve can not be used to regulate pressure and flow for a long time. Otherwise, the sealing surface of globe valve may be eroded by medium and the sealing performance may be destroyed.
Globe valves can be used in water, steam, shrinkage air and other pipelines, but they are not suitable for medium pipelines with high viscosity, easy coking and precipitation, so as to avoid damaging the sealing surface.
The working principle of globe valve is that the disc of globe valve moves vertically along the center line of the seat, and depends on the spinning of the stem thread, so that the sealing surface of the disc of globe valve and the sealing surface of the seat are closely adhered together, thus cutting off the flow of medium.
Advantages and disadvantages of globe valves
Advantages of Globe Valve
Globe valve has small working stroke and short opening and closing time.
The globe valve has good sealing property, small friction between sealing surfaces and long service life.
The globe valve has good regulating performance.
The disadvantage of globe valve is
The installation length of globe valve is larger, and the resistance of medium flow is larger.
Globe valves are complex in structure and difficult to manufacture and maintain.
The flow of globe valve passes through the valve seat from bottom to top, which has great resistance and requires great force when opening and closing.
Globe valves are generally not suitable for medium with particles, high viscosity and easy coking.
Globe valves are often used in pipelines requiring full-open and full-closed operation, and steam pipelines are more commonly used. Connection between globe valve and pipeline, either screwed or flanged.
Post time: Oct-10-2019