A three-piece welded ball valve is a type of valve whose closing element (ball) rotates around the center line of the valve body to achieve opening and closing. This type of valve is mainly used in pipelines for shut-off, distribution, and changing the flow direction of media. Its structure mainly consists of a valve body (divided into left and right valve covers and a central main valve body), a ball, a valve seat, a valve stem, and sealing rings. These components are connected together by bolts and other fasteners to form a complete valve structure.
Structural Features
Three-piece Structure:
Left body, right body, and middle body: The valve body consists of three independent parts connected by bolts or welding, facilitating the installation, disassembly, and maintenance of internal components.
Disassembly: Compared to one-piece ball valves, the three-piece structure eliminates the need to disassemble the entire piping system during maintenance; only the valve body needs to be removed.
Welded Connection:
High Strength: Welded connections provide higher structural strength, suitable for high-pressure and high-temperature conditions.
Good Sealing: Welded joints reduce the risk of leakage and improve system safety.
Ball Design:
Full Bore or Reduced Bore: Full bore or reduced bore balls can be selected based on flow requirements.
Floating Ball or Fixed Ball: Floating ball valves rely on medium pressure for sealing, while fixed ball valves are supported by springs or seats, suitable for high-pressure conditions.
Sealing Materials:
Soft Seal: Utilizes materials such as PTFE and PPL, suitable for low-temperature, low-pressure, and particulate-free media.
Hard Seal: Employs metal-to-metal sealing, suitable for high-temperature, high-pressure, and particulate-containing media.
Working Principle
The working principle of the imported welded three-piece ball valve is the same as that of a regular ball valve:
Open State: The through-hole on the ball aligns with the valve body channel, allowing fluid to pass freely.
Closed State: The ball rotates 90 degrees, the through-hole is perpendicular to the valve body channel, blocking fluid flow.
Applications
Oil and Natural Gas:
Oil Pipelines: Used to control the transportation of crude oil and refined oil products.
Natural Gas Pipelines: Suitable for high-pressure, large-diameter natural gas transportation.
Chemical Industry:
Corrosive Media Control: Used to transport corrosive media such as acids and alkalis.
High-Temperature and High-Pressure Processes: Suitable for high-temperature and high-pressure chemical reaction processes.
Power Industry:
Steam Systems: Used to control the flow and pressure of steam.
Cooling Water Systems: Regulates the flow of cooling water.
Shipbuilding and Marine Engineering:
Seawater Systems: Used to control the inflow and outflow of seawater.
Fuel Oil Systems: Regulates the transportation of fuel oil.