Characteristic
(1) Globe valves have a simpler structure than gate valves and are easier to manufacture and maintain.
(2) The sealing surface is not easily worn or scratched, with good sealing performance. There is no relative sliding between the valve disc and the valve body sealing surface during opening and closing, so the wear and scratches are not severe, the sealing performance is good, and the service life is long.
(3) When opening and closing, the valve disc stroke is small, so the height of the globe valve is smaller than that of the gate valve, but the structural length is longer than that of the gate valve.
(4) The opening and closing torque is large, the opening and closing process is laborious, and the opening and closing time is relatively long.
(5) The fluid resistance is high due to the tortuous medium channels inside the valve body, resulting in high fluid resistance and high power consumption.
(6) When the nominal pressure PN of the medium flow direction is ≤ 16MPa, it is generally used to flow downstream, and the medium flows upward from below the valve disc; When the nominal pressure PN is ≥ 20MPa, reverse flow is generally used, and the medium flows downwards from the valve disc to increase the sealing energy. When in use, the medium of the shut-off valve can only flow in one direction and cannot change the flow direction.
(7) The valve disc is often eroded when fully open.
The axis of the stem of the globe valve is perpendicular to the sealing surface of the valve seat. The valve stem has a relatively short opening or closing stroke and a very reliable cutting action, making it suitable for use as a medium for cutting, regulating, and throttling.
Disadvantage
1. The fluid resistance of the shut-off valve is high, and a large force is required to open and close it.
2. Globe valves are not suitable for media with particles, high viscosity, and easy coking.
3. The regulating performance of the shut-off valve is poor.
Advantage
1. The globe valve has a simple structure and is easy to manufacture and maintain.
2. The working stroke of the globe valve is small and the opening and closing time is short.
3. The globe valve has good sealing performance, low friction between sealing surfaces, and a long service life.
The types of globe valves are divided into external thread globe valves and internal thread globe valves according to the position of the valve stem thread. According to the flow direction of the medium, there are straight through globe valves, DC globe valves, and angle globe valves. Globe valves are divided into packing sealed globe valves and bellows sealed globe valves according to their sealing forms.
