The opening and closing parts of the rising stem gate valve are the gate plate, and the direction of motion of the gate plate is perpendicular to the fluid direction, and the open rod gate valve can only be fully opened and closed, and can not be adjusted and throttling.
The gate has two sealing surfaces, and the most commonly used two sealing surfaces of the mode gate valve form a wedge, wedge angle varies with the valve parameters, usually 50, and 2 52’when the medium temperature is not high. The gate of the wedge gate valve can be made into a whole, called a rigid gate; To improve its craftsmanship and compensate for the deviation of the angle of the sealing surface. This gate is called an elastic gate.
The type of open rod gate valve can be divided into wedge gate valve and parallel gate plate valve, which can be divided into single gate plate, double gate plate, and elastic gate plate; parallel gate plate valve can be divided into single gate plate and double gate plate.
According to the thread position of the valve stem, it can be divided into an open gate valve and a dark gate valve. When the open rod gate valve is closed, the sealing surface can be sealed only by the medium pressure, that is, only by the medium pressure to press the sealing surface of the gate to the other side of the valve seat to ensure the sealing of the sealing surface, which is self-sealing.
Most of the gate valves is using forced sealing, that is, when the valve is closed, it relies on external force to force the gate pressure to the valve seat, to ensure the sealing of the sealing surface.
Open-lever gate valve has the following advantages:
(1)The fluid resistance is small
(2)The sealing surface is less erosion and erosion by the medium.
(3)It’s easier to open and close.
(4)Media flow direction is not restricted, no turbulence, do no reduce the pressure.
(5)Simple body, short structure length, good manufacturing technology, and a wide range of applications.
(6)The disadvantages of the open gate valve are as follows:
(7)It is easy to cause erosion and abrasion between the sealing surfaces, and the maintenance is more difficult.
(8)The external size is large, open needs a certain space, open and close time is long.
(9)The structure is more complex.
The type of gate valve, according to the sealing surface configuration can be divided into wedge gate valve and parallel gate valve, wedge gate valve can be divided into: single gate pole, double gate plate and elastic gate valve; parallel gate valve can be divided into single gate plate and double gate plate. According to the thread position of the valve stem, it can be divided into open gate valve and dark gate valve.