Introduction to Basic Knowledge of Electric Ball Valves
Electric ball valves (English: Electric Ball Valves) consist of an electric actuator integrated with a ball valve assembly. As critical pipeline pressure components in industrial automation process control systems, they are primarily used for remote on/off control (connecting or isolating media) in pipeline systems. According to the GB/T21465-2008 standard "Valve Terminology," they are defined as valves where the opening/closing element (the ball) is driven by the valve stem and rotates around its axis. These valves are widely employed to cut off, regulate, or divert pipeline media.
The hard-sealed V-type ball valve features a V-shaped ball core and a welded hard-alloy metal valve seat, providing exceptional shear resistance, making it ideal for handling fibrous media or fluids containing fine solid particles.
Classification of Electric Ball Valves
Electric ball valves are categorized based on connection type and sealing mechanism:
By Connection Type
Flanged electric ball valves
Socket-weld electric ball valves
Butt-weld electric ball valves
Threaded electric ball valves
By Sealing Mechanism
Soft-sealed electric ball valves (PTFE, elastomeric seats)
Hard-sealed electric ball valves (metal-to-metal seats)
By Structural Design
Floating ball valves
Fixed ball valves
Track ball valves
V-port ball valves
Three-way ball valves
Stainless steel ball valves
Forged steel ball valves
Ash discharge ball valves
Sulfur-resistant ball valves
Pneumatic ball valves
Key Structural Types & Operating Principles
1. Floating Ball Design
The ball is free to move slightly under media pressure, pressing against the downstream seal to ensure tight shutoff.
Advantages: Simple structure, reliable sealing.
Disadvantages: The sealing ring bears full media load, limiting suitability for high-pressure applications.
Applications: Low-to-medium pressure systems.
2. Fixed Ball Design
The ball is rigidly mounted and does not shift under pressure.
Floating valve seats compensate for seal wear, ensuring tight closure.
Equipped with anti-friction bearings to reduce operating torque, making them ideal for high-pressure, large-diameter valves.
Lubrication systems enhance sealing and reduce torque further.
3. Elastic Ball Design
The ball features an elastic groove, allowing controlled deformation for improved sealing.
Metal-to-metal sealing withstands high temperatures and pressures.
The wedge-action stem expands the ball during closure, minimizing friction during operation.
Structural Overview & Performance Characteristics
Design Advantages
Compact & lightweight: Fewer components reduce material usage and installation space.
Quick 90° operation: Enables fast open/close cycles with low torque.
Excellent flow control: Minimal pressure drop due to full-bore design.
Dual sealing options:
Elastic seals (PTFE, rubber) for leak-tight performance.
Metal seals for high-temperature/pressure endurance.
Material Options
Body materials: WCB, CF8 (304), CF8M (316), titanium.
Seat materials: PTFE, reinforced polymers, tungsten carbide.
Performance Parameters
Temperature: -20°C to +150°C (up to +250°C with special seals)
Pressure: PN16 to PN100
Media: Air, steam, water, gas, petroleum, chemicals, corrosive fluids
Applications & Industry Use
Electric ball valves are indispensable in:
Oil & gas pipelines (shutoff, regulation)
Chemical processing (corrosive media handling)
Power plants (cooling water systems)
Water treatment (flow diversion)
HVAC systems (steam control)
V-Port Ball Valve Advantages
Precision flow control even at low rates.
Self-cleaning action from shear effect between V-notch and seat.
Fiber/solid particle resistance—ideal for slurry applications.
Installation, Maintenance & Troubleshooting
Installation Checks
Perform multiple open/close cycles to verify smooth operation.
Conduct pressure tests to confirm flange seal integrity.
Common Failures & Solutions
Motor overload: Caused by low voltage, incorrect torque settings, or excessive ambient heat.
Stem leakage: Often due to seal degradation—replace O-rings/gaskets.
Actuator failure: Check control circuits and power supply stability.
Maintenance Best Practices
Depressurize before disassembly.
Use compatible cleaners (e.g., gasoline for metal parts, alcohol for non-metallics).
Avoid prolonged soaking of seals to prevent swelling.
Reassemble with even bolt tightening to prevent distortion.
Technical Specifications
Nominal Diameter: DN50–DN350
Pressure Rating: PN1.6–25MPa
Drive Type: Electric (with optional manual override)
Explosion-proof Options: Available for hazardous environments
Conclusion
Electric ball valves are versatile, durable, and efficient, making them the preferred choice for modern fluid control systems. Their adaptability across industries—from oil refineries to water treatment plants—stems from robust construction, precise actuation, and low maintenance needs. Proper selection based on media, pressure, and temperature ensures optimal performance and longevity.
For specialized applications (e.g., cryogenic, high-purity), consult manufacturers for customized solutions.
