1. Core driving mechanism
The ball rotates to control the flow channel
The fully welded ball valve drives the internal ball to rotate 90° through the valve stem, and uses the alignment or misalignment of the circular or L/T-shaped channel on the ball and the valve seat to achieve full opening, full closing or flow direction switching of the medium.
Fully open state: The axis of the ball channel completely coincides with the pipeline, and the flow resistance approaches zero; Fully closed state: The ball channel is perpendicular to the pipeline, completely blocking the flow of the medium.
Drive mode
Manual/electric/pneumatic drive: The electric or pneumatic actuator drives the valve stem to rotate through the output shaft, and the response speed is fast (the electric type supports remote signal control, such as 4~20mA signal).
2. Structure and movement process
Decomposition of opening and closing action
Opening process:
Turn the handwheel or actuator counterclockwise, the valve stem is lifted in the opposite direction, the mechanical pressure on the ball is released, and the ball leaves the valve seat and starts to rotate without friction.
The spiral groove of the valve stem cooperates with the guide pin to rotate the ball to the fully open position, and the flow channel is completely unblocked.
Closing process:
The drive device is rotated clockwise, the valve stem presses down and drives the ball to rotate 90°, and finally the angular plane at the bottom of the valve stem is mechanically wedged to force the ball to seal with the valve seat.
Welding structure characteristics
The key components such as the valve body, ball and valve stem are connected by a full welding process (such as flange and valve body welding), eliminating the leakage risk of traditional bolted connections, and are suitable for high pressure (≤42.0MPa) and high temperature (≤550℃) working conditions.
3. Sealing mechanism and performance advantages Dynamic sealing design
The valve seat adopts a combination of carbonized Teflon (PTFE) sealing ring and disc spring, which pushes the valve seat to press the ball through the medium pressure, adapts to pressure and temperature fluctuations, and ensures zero leakage (ANSI VI grade).
When closing, the ball first rotates away from the valve seat, and then mechanically presses to reduce the wear of the sealing surface.
Harsh working conditions resistance
Corrosion resistance: The valve body can be made of stainless steel (such as 304, 316L), suitable for acid and alkali media and corrosive liquids.
Temperature and pressure resistance: The welded structure has high strength, and some models can withstand temperatures up to 550°C and pressures up to PN420 (42.0MPa).
IV. Typical application scenarios
Petrochemical industry: High-pressure oil and gas pipeline opening and closing control, welded structure leakage prevention.
Electricity and heating: High-temperature steam pipeline regulation, excellent temperature resistance.
Environmental protection and water conservancy: Sewage and corrosive media transportation, reliable sealing and low maintenance cost.