Solid wedge gate valve is a basic type of wedge gate valve. Its core feature is the use of an integrally cast or forged rigid wedge gate plate, which is sealed by mechanical compression of the wedge angle. It is suitable for scenes with high pressure, high temperature and high sealing requirements (such as oil and natural gas pipeline control).
Core structure and design points
- Rigid wedge gate plate design
The gate plate is an integral structure that cannot be deformed (such as a single gate plate), and the sealing surface is at a specific angle to the vertical center line (usually 2°52', 3°30', 5°, etc.), forming a wedge-shaped sealing pair;
When closed, the valve seat is forced to be pressed by the valve stem thrust, and the positive pressure of the sealing surface is increased by the wedge angle to achieve high-strength sealing.
- Valve seat and sealing surface match
The valve seat sealing surface is fully matched with the wedge gate plate to ensure 360° contact in the fully closed state and reduce the risk of medium leakage;
The common sealing surface material is hard alloy or surfacing Stellite coating to improve wear resistance and high temperature adaptability.
Working principle and performance advantages
- Sealing mechanism:
During the closing process, the wedge gate relies on mechanical force to embed into the valve seat to form a self-enhanced sealing force, which is especially suitable for medium pressure fluctuations or low pressure conditions;
The contact pressure of the sealing surface increases with the increase of medium pressure, which enhances the sealing reliability (such as high-pressure steam pipeline scenarios).
- Performance advantages:
High temperature and high pressure resistance: The overall rigid structure can withstand the thermal expansion stress under high temperature to avoid seal failure caused by gate deformation;
Long life: The hard seal design reduces particle erosion or wear of corrosive media and extends the maintenance cycle.
- Applicable scenarios and limitations
Typical applications:
High-pressure cutoff of oil and natural gas transmission pipelines;
High-temperature valve control of the main steam system of thermal power plants;
Medium isolation with strict sealing requirements in chemical plants.
- Limitations:
The processing accuracy requirements are extremely high, and the angle deviation of the sealing surface is easy to cause jamming or leakage;
Frequent temperature changes may cause the gate and valve seat to bite due to thermal expansion and contraction (need to cooperate with elastic valve seat or preload adjustment design).
