Ball valves can be divided into the following three main types according to their structure, drive mode and functional characteristics. Each type has significant differences in application scenarios, operation methods and performance characteristics:
1. Classification by structure
Floating Ball Valve
Structural features: The ball has no fixed support and is only pressed against the outlet by the valve seat pressure to achieve sealing.
Working principle: The medium pressure pushes the ball to move toward the outlet, squeezing the valve seat to form a seal.
Application scenarios: medium- and low-pressure pipelines (≤6.4 MPa), such as water treatment and HVAC systems.
Advantages and disadvantages:
Advantages: Simple structure and low cost.
Disadvantages: The valve seat is easy to wear under high pressure, and the sealing is affected by medium pressure fluctuations.
Trunnion Ball Valve
Structural features: The ball is fixed by the upper and lower shafts, and the valve seat is sealed by spring or hydraulic loading.
Working principle: The valve seat actively fits the ball, and the sealing force is independent of the medium pressure.
Application scenarios: High-pressure, large-diameter pipelines (such as oil and gas transportation, chemical processes).
Advantages and Disadvantages:
Advantages: reliable sealing, high pressure resistance, and small torque.
Disadvantages: complex structure and high cost.
Flexible Ball Valve
Structural features: the ball has an elastic groove, which deforms elastically after being compressed to achieve sealing.
Working principle: the medium pressure shrinks the elastic groove of the ball and squeezes the valve seat to seal.
Application scenarios: medium- and high-pressure pipelines (such as high-temperature steam and corrosive media).
Advantages and Disadvantages:
Advantages: good sealing and adaptability to high temperature.
Disadvantages: The elastic groove is easy to fatigue and has a short life.
2. Classification by driving method
Manual Ball Valve
Driving method: operated by handle, gear, or worm gear drive.
Application scenarios: small pipelines, low-frequency switches (such as household water supply, laboratory equipment).
Features: simple structure, low cost, but cannot be remotely controlled.
Electric Ball Valve
Driving method: driven by a motor and can be remotely controlled.
Application scenarios: automation systems (such as building automation and industrial process control).
Features: fast response and programmable, but requires power support.
Pneumatic Ball Valve
Drive mode: cylinder operation driven by compressed air.
Application scenario: explosion-proof environment (such as chemical industry, oil, and gas).
Features: fast action, safe and reliable, but requires an air source.
III. Classification by functional characteristics
General Purpose Ball Valve
Functional features: standard sealing structure, suitable for general media (such as water and air).
Application scenario: ordinary industrial pipelines, civil systems.
Example: cast iron ball valve, brass ball valve.
Sanitary Ball Valve
Functional features: full-coverage sealing, no dead angle design, and in line with food-grade standards.
Application scenario: food, pharmaceutical, bioengineering.
Example: 316L stainless steel ball valve, clamp connection ball valve.
Special Service Ball Valve
Functional features: designed for high temperature, high pressure, and corrosive media.
Application scenarios: extreme working conditions (such as deep-sea mining and nuclear power plants).
Examples: high-temperature ball valve (temperature resistance 600℃+), low-temperature ball valve (temperature resistance -196℃), corrosion-resistant ball valve (Hastelloy material).
IV. Type comparison and selection recommendations
Type Applicable scenarios Core advantages Notes
Floating ball valve Medium- and low-pressure, small- and medium-diameter pipelines Low cost, simple structure Cautious selection for high-pressure working conditions
Fixed ball valve High pressure, large diameter, frequent operation Reliable sealing, small torque High cost
Electric ball valve Automation system, remote control Fast response, programmable Power supply support is required, and maintenance is complex.
Sanitary ball valve Food, pharmaceutical industry Aseptic design, easy to clean The material must meet food-grade standards.
Special working condition ball valve Extreme temperature, corrosive media Strong adaptability, long life Customized design is required, and the cost is high.
V. Summary
Select by structure: Select a floating ball valve or a fixed ball valve according to pressure and diameter.
Select by drive mode: Select manual, electric, or pneumatic according to automation requirements.
Selection by functional characteristics: select general-purpose, sanitary, or special-condition ball valves according to the characteristics of the medium.
By clarifying the application scenario and performance requirements, the ball valve type can be accurately matched to ensure safe and efficient operation of the system.