Globe valve, also known as shut off valve, stop valve, isolating valve, is a mandatory sealing valve, so when the valve is closing, pressure must be applied to the valve disc to force the sealing surface not to leak.
According to the position of the stem thread, the globe valve can be divided into external thread globe valve and internal thread globe valve; according to the flow direction of the medium, the globe valve can be divided into straight-through globe valve, oblique globe valve, angle globe valve; according to the sealing type, the globe valve can be divided into packing sealing globe valve, and bellows seal globe valve.
the characteristics of the globe valve
1.1. the structure of the globe valve is simpler than that of the gate valve, and the manufacturing and maintenance of the globe valve are more convenient.
1.2. the sealing surface of the globe valve is not easy to be worn and scratched, and the sealing performance is good. When the globe valve is opening and closing, there is no relative sliding between the valve disc and the body sealing surface. So the wear and abrasion are not serious, the sealing performance is good, and the service life is long.
1.3. when the globe valve is opening and closing, the valve disc stroke is short, therefore, the height of the globe valve is smaller than that of the gate valve, but the face to face length of the globe valve is longer than that of the gate valve.
1.4. the opening and closing torque of the globe valve is large, and it is laborious to open and close the globe valve, the opening and closing time of the globe valve is long.
1.5. the fluid resistance is large, because the medium channel inside the valve body is tortuous, and once the flow resistance is large, the power consumption is large.
1.6. When the nominal pressure of the medium flow direction is PN≤16Mpa, the forward flow is generally adopted, the medium flows upward from the bottom of the valve disc; when the nominal pressure PN≥20MPa，the counter current flow is generally adopted, and the medium flows downward from the top of the valve disc, to increase the sealing performance. When the globe valve is used, the medium in the globe valve can only flow in one direction, and can not change the flow direction.
1.7. when the globe valve is fully open, the valve disc is often eroded.
The stem axis of the globe valve is perpendicular to the sealing surface of the valve seat sealing surface. The opening and closing stroke of the valve stem is relatively short, and the globe valve has a very reliable shut-off action, which makes the globe valve suitable for shutting off the medium, regulating the flow and throttling.