A Globe Valve is a valve that moves the closing member (valve) along the seat centerline and has a very reliable cut-off function. As the Globe Valve flap between the opening of the small travel, sealing surface can withstand multiple opening and closing, so it is suitable for frequent switching occasions.
The use of the Globe Valve is very common, but because of the large opening and closing torque, the structure length is longer, usually the nominal pass are limited to 250mm below, there are to 400mm.
When the selection of the need to pay special attention to the direction of import and export, generally more than 150mm Globe Valve medium mostly from the bottom of the valve into the closure of the operating force is greater than open, and more than 200mm stop valve medium mostly from the top of the valve into the open operation force is greater than closed The This is due to the closing torque of the valve. In order to reduce the opening or closing torque, more than 200mm Globe Valve can be set within the bypass valve or bypass valve.
The most obvious advantages of the globe valve are:
1. The opening height is generally only 1/4 of the diameter of the seat passage and is therefore much smaller than the gate valve.
2. In the opening and closing process, because the valve flap in the valve body sealing surface friction between the valve than the small, so wear.
3. Usually in the valve body and the valve only one sealing surface, so the manufacturing process is better, easy to repair.
Gate valve opening and closing parts is the gate, the direction of movement of the gate and the fluid direction perpendicular to the gate valve can only be fully open and fully closed, not suitable for regulation and throttling.
When the gate valve is closed, the sealing surface can only be sealed by the medium pressure, that is, by means of the medium pressure to press the sealing surface of the gate to the other side of the valve seat to ensure that the sealing surface of the seal, which is self-sealing. Most of the gate valve is forced to seal, that is, when the valve is closed, to rely on external force forced to the gate pressure to the valve seat to ensure that the sealing surface of the seal.
The gate has two sealing surfaces. The two most commonly used wedge gate valves are wedge-shaped, and the wedge angle varies with the valve parameters, usually 5 °. Wedge gate valve can be made into a whole, called the rigid gate; can also be made to produce a trace of the deformation of the gate to improve its craft, to make up the sealing surface angle in the processing of the deviation, Plate is called elastic gate.
Gate valve has the following advantages:
1. opening and closing more effort.
2. Fluid resistance is small, the sealing surface by the medium erosion and erosion of small.
3. Simple shape, short structure length, manufacturing process is good, wide range of applications.
4. Media flow is not restricted, no spoiler, no reduction in pressure.