High-pressure valve refers to the nominal pressure (PN) between 10 and 80 MPa valves, belonging to the industrial piping system for controlling the flow of high-pressure media key equipment. Its core features and technical points are as follows:
First, the main structure type
High pressure gate valve
The opening and closing parts are gates, the movement direction is perpendicular to the fluid, only support full open or full close operation, can not regulate the flow.
Adopting forced sealing design, pressure needs to be applied to ensure the tightness of the sealing surface when closing.
Typical materials include carbon steel, stainless steel, etc., suitable for petroleum, chemical and electric power fields.
High Pressure Ball Valve
The opening and closing parts are spheres, which can be switched on and off by rotating 90 degrees, and the sealing surface is not easy to be eroded by the medium.
Compact structure, suitable for natural gas, hydraulic machinery and other high-pressure scenes, the material covers metal and non-metallic sealing materials.
Second, the sealing technology characteristics
Multi-stage sealing design
Seat seal: metal hard seal is mostly used in high-pressure environment, and some ball valves use PTFE and other non-metallic materials for soft seal.
Stem seal: commonly used flexible graphite ring or O-ring, high temperature conditions need to enhance the strength of the material.
Middle seal: metal wound gasket or pressure self-sealing structure (PSB).
Anti-leakage test
The sealing is tested by gas injection method, for example, the patented technology of using the non-return component to prevent the backflow of water, and the leakage is observed through the gas bubbles.
III. Typical Application Scenarios
Energy industry: high-temperature and high-pressure pipelines in power stations, natural gas transmission systems.
Chemical industry: strong corrosive media and high-pressure reaction device.
Industrial equipment: hydraulic machinery, petroleum refining equipment.
Fourth, and the difference between low-pressure valves
Pressure level: high pressure valve working pressure is significantly higher than the low pressure valve (usually ≥ 10 MPa).
Material strength: the need to use high-strength metals and special sealing structure to withstand high-pressure impact.
Design complexity: the sealing system is more complex, need to take into account high temperature, corrosion resistance and other performance
