Introduction to the Function, Principle, and Characteristics of Globe Valves

 Globe valves are used to cut off the flow of media, and are suitable for situations that require frequent opening. The sealing parts of a globe valve are the valve disc and valve seat. In order to ensure a tight closing of the globe valve, the mating surface of the valve disc and valve seat should be ground or a gasket should be used. The sealing surface can also be embedded with corrosion-resistant and wear-resistant materials such as bronze and stainless steel.The valve disc and valve stem of the globe valve are connected in a movable manner to ensure a tight fit between the valve disc and valve stem. The lifting and lowering of the valve disc of a globe valve is generally controlled by the valve stem. The upper part of the valve stem is a handwheel, and the middle part is a threaded and packing sealing section. The function of the packing is to prevent the internal medium of the valve body from leaking along the valve stem.

The function of a shut-off valve

1、 The main function of a shut-off valve in a pipeline is to cut off or connect fluid. The regulating flow of a shut-off valve is better than that of a gate valve. However, a shut-off valve cannot be used to regulate pressure and flow for a long time. Otherwise, the sealing surface of the shut-off valve may be eroded and corroded by the medium, which may damage the sealing performance.
2、 Globe valves can be used in pipelines such as water, steam, and compressed air, but they are not suitable for medium pipelines with high viscosity, easy coking, and sedimentation to avoid damaging the sealing surface.

The principle of a shut-off valve

The valve disc of the globe valve moves vertically along the centerline of the valve seat, relying on the spinning of the valve stem thread to make the sealing surface of the valve disc of the globe valve closely adhere to the sealing surface of the valve seat, thereby blocking the flow of medium.

Advantages of shut-off valves

1. Small work schedule and short opening and closing time.
2. Good sealing performance, low friction between sealing surfaces, and long service life.
3. Good regulation performance.

Disadvantages of shut-off valves

1. The installation length is relatively long, and the resistance to medium flow is high.
2. The structure is relatively complex, making manufacturing and maintenance difficult.
3. The fluid passes through the valve seat from bottom to top, with high resistance and a greater force required for opening and closing.
4. Not suitable for media with particles, high viscosity, and easy coking.

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