Working principle of Globe Valve

The globe valve regulates the flow in the pipeline. It is used to control or prevent the flow of liquid or gas through pipes. The globe valve is named after the shape of its spherical valve body. The two halves of the valve body are separated by an internal baffle.Although these valves have a slightly higher pressure drop than gate/ball valves, they can be used where the pressure drop across the valve is not a controlling factor. Globe valves are also called throttle valves. This article is all about the working principle of the globe valve.

The following knowledge points are listed below:

• The working principle of globe valve

• The category of globe valve

1.  The working principle of globe valve

Globe valve, also known as globe valve, is one of the most commonly used valves. Shut-off valves are popular because of the small friction between the sealing surfaces when they are closed, long service life, low lifting height, and easy manufacturing and maintenance. The globe valve is not only suitable for medium and low pressure, but also suitable for high pressure. The working principle of the globe valve is to rely on the pressure of the valve stem to tightly combine the sealing surface of the disc valve seat and the sealing surface of the valve seat to prevent the passage of the medium. The ball valve only allows the medium to flow in one direction. Therefore, the shut-off valve is directional during installation. The size of the end face of the globe valve is larger than that of the gate valve. At the same time, for high-fluid resistance globe valves, the sealing performance is poor during long-term operation. The globe valve is a forced sealing valve. For this reason, pressure should be applied when closing the valve to force the sealing surface to not leak. When the medium enters the valve from the bottom of the disc, the resistance that the operating force should overcome is the thrust generated by the friction between the valve stem and the packing. The force to close the valve is greater than the force to open the valve. Nevertheless, the diameter of the valve stem should be large to prevent the valve stem from bending.

2. The category of globe valve

1.Globe valve can be divided into:

(1) Straight cut-off valve

(2) Straight-through globe valve (Y-type globe valve): The straight-through globe valve (Y-type globe valve) has a slanted line between the body channel and the main channel. Therefore, the flow conditions are less destructive than traditional globe valves, and the pressure loss through the valve is relatively small.

(3) Angle cut-off valve: The angle cut-off valve changes the flow direction only once, and the pressure drop through the angle cut-off valve is smaller than that of the conventional cut-off valve.

(4) Plunger stop valve: The plunger stop valve is a kind of deformed conventional stop valve. The valve disc and valve seat generally adopt the plunger principle. The disc is polished into the plunger and connected to the valve stem. The seal is achieved by two elastic sleeves on the plunger. The two elastic seals are separated by a light ring, which is compressed by the load exerted on the bonnet by the nut. The elastic ring is replaceable and can be made of various materials. Valves are mainly used to connect or cut off pipes. However, with a special plunger or ring, the plunger shut-off valve can also be used to regulate the flow.

2. According to the position of the thread on the valve stem, the globe valve can be divided into:

(1)External spiral stem stop valve: The thread on the stem is located outside the valve body. The valve stem is not corroded by the medium and is convenient for lubrication. This structure is very common.

(2) Internal thread stem stop valve: The thread on the stem is located in the valve body. The thread is in direct contact with the medium and is easily corroded. This structure cannot be lubricated. This structure is suitable for small diameter and low temperature occasions.

Now i would assume that you know how the globe valves works.