Distinguishing Between Pneumatic Butterfly Valves and Pneumatic Ball Valves

Pneumatic butterfly valves and pneumatic ball valves are both extensively employed in industrial fluid control systems; however, they exhibit variations in terms of application suitability, operation, and design.  The selection of the appropriate valve for a particular process is facilitated by an understanding of their differences.

1. Construction and Design

Pneumatic ball valve

• Consists of a rotating spherical disc (ball) with a bore that either permits or impedes passage.

• Available in both full-port (full bore) and reduced-port (standard bore) designs.

• Typically, the body is composed of two or three pieces, with fastened connections.

Pneumatic Butterfly valve

• Utilizes a rotating shaft that rotates 90° to regulate flow, which is mounted on a circular disc.

• in comparison to ball valves, they are compact and lightweight.

• The flow efficiency is slightly reduced by the disc's continued presence in the flow path, even when it is completely open.

2. Capabilities for Flow Control

Pneumatic ball valve

• Ideal for on/off applications (not suitable for modulating due to erosion caused by high-velocity flow).

• Minimal pressure reduction is provided by full-port designs.

Pneumatic Butterfly valve

• Suitable for both on/off and throttling (improved flow control at partial angles).

• The disc's presence in the flow path results in a slightly higher pressure decrease.

3. Temperature and Pressure Range

 Pneumatic ball valve

• A greater tolerance for pressure (up to 1000+ psi in certain models).

• Performs exceptionally well in high-temperature applications (subject to the seat material).

 Pneumatic Butterfly valve

• Restricted to moderate pressure ranges (typically 150-250 psi).

• Certain high-performance butterfly valves are capable of managing higher pressures.

• Temperature resistance is contingent upon the material of the seat (e.g., EPDM, PTFE).

4. Leakage Prevention and Sealing

Pneumatic ball valve

• Zero leakage in shut-off applications due to bubble-tight encapsulation.

• Abrasive media are more effectively managed by varieties that are seated in metal.

Pneumatic Butterfly valve

• While soft-seated versions (EPDM, PTFE) provide exceptional encapsulation, they may degrade when subjected to high temperatures or pressures.

• In comparison to ball valves, they are more susceptible to minimal leakage in high-pressure applications.

5. Weight and Space Factors

Pneumatic ball valve

• Particularly in larger sizes, the item is heftier and bulkier.

• Necessitates additional installation space.

Pneumatic Butterfly valve

• Compact and lightweight, it is well-suited for pipes with large diameters and restricted spaces.

• Installation is simpler in small spaces.

6. Maintenance and Cost

Pneumatic ball valve

• Initial costs are generally higher, particularly for full-bore designs.

• Greater complexity in maintenance is a result of the presence of numerous sealing points.

Pneumatic Butterfly valve

• Particularly for applications with a large diameter, it is more cost-effective.

• Simpler maintenance (easier seat replacement, fewer moving elements).

7. Applicability

Pneumatic Ball Valve

Optimal for: High-pressure or high-temperature systems (chemical facilities, oil and gas).

Applications necessitating zero leakage, such as gas conduits.

Throttling is replaced with on/off control.

Pneumatic Butterfly Valve

Optimal for: Large-diameter, low-to-medium pressure systems ( HVAC, water treatment).

Controlling and moderating the flow of products (pharmaceuticals, food and beverage).

Projects that are cost-sensitive and require careful consideration of space and weight.