The pneumatic three-piece welded ball valve is a pneumatic ball valve adopting a three-piece body structure with butt-weld ends. It is mainly used for rapid on-off, reliable shut-off and remote automatic control in industrial pipelines.
The valve features a detachable three-piece construction for easy maintenance and replacement of the internal ball, seats and seals. Butt-weld connections at both ends allow direct welding to piping, forming a continuous and compact pipeline system with reliable joints, fewer leakage points and excellent pressure resistance.
Working Principle of Pneumatic Three-Piece Welded Ball Valve
The pneumatic three-piece welded ball valve uses a pneumatic actuator as the drive unit. Clean compressed air enters the actuator, driving its internal transmission mechanism to generate 0°～90° quarter-turn torque, which rotates the valve stem and ball core synchronously. The valve opens fully when the bore of the ball core aligns with the pipeline flow passage for normal medium flow; rotating the ball core by 90° closes off the passage to cut off the medium.
It can be fitted with solenoid valves, limit switches, air filter regulators and other accessories for remote control and valve position feedback. The single-acting actuator incorporates an internal spring for automatic reset upon loss of air supply to satisfy fail-safe requirements. The three-piece valve body allows easy disassembly for maintenance, while butt-weld connections guarantee the overall tightness and pressure resistance of the pipeline.
Pneumatic Shut‑off Ball Valve are 0‑90° rotary valves. They utilize pneumatic actuators to convert compressed air into rotary motion, delivering fast and reliable valve opening and closing for industrial process control.
According to specific application requirements, pneumatic ball valves can be equipped with solenoid valves, limit switches, position feedback devices, air filter‑regulators, valve positioners and other pneumatic instrument accessories to realize automatic valve control and remote monitoring functions.
Many factors shall be considered when selecting a pneumatic ball valve, including valve size, pressure rating, operating temperature, process medium, flow rate, body material, seat material, actuator type and control mode.
If you are looking for a qualified manufacturer or supplier of pneumatic ball valves, please contact our technical team and provide your operating conditions. Our valve engineers will recommend suitable pneumatic ball valves, actuators and control accessories based on your specific application requirements. （Unit: mm）
| DN | NPS | Type/Class | Part No | d | L | H | W | D | |
|---|---|---|---|---|---|---|---|---|---|
| DN15 | 0.5 | 3Q661-PN16 | 3Q661150XLX05 | 15 | 70 | 50 | 95 | 22.0 | |
| DN20 | 0.75 | 3Q661-PN16 | 3Q661150XLX075 | 20 | 78 | 60 | 110 | 26.5 | |
| DN25 | 1 | 3Q661-PN16 | 3Q661150XLX1 | 25 | 92 | 66 | 125 | 31.2 | |
| DN32 | 1.25 | 3Q661-PN16 | 3Q661150XLX125 | 32 | 102 | 78 | 135 | 39.3 | |
| DN40 | 1.5 | 3Q661-PN16 | 3Q661150XLX15 | 38 | 111 | 85 | 140 | 47.2 | |
| DN50 | 2 | 3Q661-PN16 | 3Q661150XLX2 | 50 | 138 | 95 | 165 | 57.2 | |
| DN65 | 2.5 | 3Q661-PN16 | 3Q661150XLX25 | 65 | 178 | 123 | 220 | 74.0 | |
| DN80 | 3 | 3Q661-PN16 | 3Q661150XLX3 | 78 | 198 | 140 | 220 | 90.3 | |
| DN100 | 4 | 3Q661-PN16 | 3Q661150XLX4 | 100 | 242 | 156 | 300 | 111.0 |
Boasting a three-piece structure for convenient maintenance, the valve adopts welded connections to minimize leakage points. With pneumatic actuation for rapid on-off operation and a straight passage offering low flow resistance, it achieves dependable sealing. The butt-weld design creates a compact piping layout, supports flexible automation setups, and suits a broad scope of working conditions.
