The pneumatic hemispherical valve is an automated control valve that combines a pneumatic actuator with an eccentric hemispherical valve structure, and is widely used in the field of industrial fluid control.
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Pneumatic Hemisphere Valve Technical parameters
Caliber: DN100-DN1400
Design and manufacture:GB/T 12237-1989
Inspection and test:GB/T 13927-1992
Flange connection:GB/T 9113.1-2000
Structure length:JD-2004
Pressure temporature levol: GB/T12224
Drive mode: Pneumatic, Electric, Manual
Pressure: PN1.0MPa-PN1.6MPa
Pneumatic Hemisphere Valve Main Components Material
| Body | Grey cast iron | Ductile Iron | Cast steel |
| Bonnet | Grey cast iron | Ductile Iron | Cast steel |
| Stem | 2Cr13 | 2Cr13 | 2Cr13 |
| Seat | Stainless steel | Stainless steel | Stainless steel |
| Spherical | Ductile iron cover rubber, stainless steel | Stainless steel | Rubber covered steel / stainless steel |
| Hemisphere | Grey cast iron | Ductile Iron | Cast steel |
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Pneumatic Hemisphere Valve Main Connection Dimensions (mm) – Nominal Pressure: 1.0 MPa
| DN | L | D | K | d | b | z–dØ | Hw |
|---|---|---|---|---|---|---|---|
| 100 | 229 | 220 | 180 | 156 | 22 | 8–18 | 330 |
| 125 | 254 | 250 | 210 | 184 | 22 | 8–18 | 345 |
| 150 | 267 | 285 | 240 | 211 | 24 | 8–22 | 370 |
| 200 | 292 | 340 | 295 | 266 | 24 | 8–22 | 405 |
| 250 | 330 | 395 | 350 | 319 | 26 | 12–22 | 480 |
| 300 | 356 | 445 | 400 | 370 | 26 | 12–22 | 520 |
| 350 | 430 | 505 | 460 | 429 | 26 | 16–22 | 570 |
| 400 | 530 | 565 | 515 | 480 | 26 | 16–26 | 630 |
| 450 | 580 | 615 | 565 | 530 | 28 | 20–26 | 690 |
| 500 | 660 | 670 | 620 | 582 | 28 | 20–26 | 740 |
| 600 | 840 | 780 | 725 | 682 | 34 | 20–30 | 840 |
| 700 | 900 | 895 | 840 | 794 | 34 | 24–30 | 960 |
| 800 | 1000 | 1015 | 950 | 901 | 36 | 24–33 | 1080 |
| 900 | 1100 | 1115 | 1050 | 1001 | 38 | 28–33 | 1190 |
| 1000 | 1200 | 1230 | 1160 | 1112 | 38 | 28–36 | 1310 |
| 1200 | 1300 | 1455 | 1380 | 1328 | 44 | 32–39 | 1420 |
| 1400 | 1500 | 1675 | 1590 | 1530 | 48 | 36–42 | 1540 |
Pneumatic Hemisphere Valve Structural Features
Eccentric Hemispherical Design
The valve body adopts an eccentric structure, with an eccentric angle (typically 10°-30°) between the ball and the valve seat. This allows the ball to quickly disengage from the valve seat during opening, reducing friction and wear.
The ball surface can be covered with wear-resistant materials (such as hard alloys, ceramics, etc.) to adapt to high-hardness and particulate media conditions.
Pneumatic Actuator
Composed of a cylinder, piston, spring, etc., compressed air drives the piston to rotate, causing the valve stem to move linearly, thus opening and closing the valve.
Can be equipped with accessories such as solenoid valves and positioners to achieve remote control, proportional regulation, or intelligent control.
Sealing Structure
Utilizes a bidirectional sealing design. The contact surface between the valve seat and the ball is metal or a soft seal (such as PTFE), ensuring zero or low leakage requirements.
Some models are equipped with self-lubricating sealing rings to extend service life.
Pneumatic Hemisphere Valve Working Principle
Opening Process
Air supply enters the cylinder through the solenoid valve, pushing the piston to rotate 90° (or move linearly), causing the ball to disengage from the valve seat, allowing fluid to pass through.
The eccentric structure allows the ball to quickly disengage from the sealing surface during the initial opening phase, reducing friction.
Closing Process
The air supply direction is reversed; a spring or reverse air pressure pushes the piston back to its original position, pressing the ball against the valve seat to achieve a seal.
The eccentric design ensures the ball automatically centers upon closing, guaranteeing a reliable seal.
Pneumatic Hemisphere Valve Applications
Mining and Metallurgy
Transporting highly abrasive media such as slurry, tailings, and metal powder.
Power Industry
Boiler feedwater, ash and slag treatment, flue gas desulfurization systems, etc.
Chemical and Petroleum
Transporting corrosive or particulate-containing chemical raw materials, oil products, etc.
Water Treatment
Wastewater treatment, sludge transportation, chemical dosing systems, etc.
Paper and Pulping
Controlling high-viscosity media such as pulp transportation and black liquor treatment.
Pneumatic Hemisphere Valve factory
