Valves that are not classified as full bore

Valves that are not classified as full bore typically have a smaller internal diameter than the nominal diameter of the pipe they are connected to, which may result in restrictions on flow. Here are common types of reduced bore and non-full bore valves:

1. Reduced Bore Ball Valve

• Description: The internal diameter of the ball valve is smaller than the piped diameter.
• Use: Suitable for applications where space and weight are critical and where slightly reduced flow is acceptable.

2. Globe Valve

• Description: The flow passage in a globe valve is designed with a throttle that creates a restriction in the flow.
• Use: Commonly used for throttling and regulating flow; provides good flow control but has higher pressure drops compared to full bore valves.

3. Gate Valve

• Description: While many gate valves can be full bore, certain designs with reduced ports exist that limit flow.
• Use: Primarily for on/off service but can be designed with reduced bores for specific applications.

4. Butterfly Valve

• Description: Certain designs of butterfly valves (especially those with concentric designs) may not provide a full bore.
• Use: Cost-effective and lightweight; used in low-pressure applications where flow control is necessary.

5. Check Valve

• Description: Some check valves, particularly swing check valves, have a reduced internal diameter.
• Use: Used to prevent reverse flow in piping systems; not ideal for applications requiring high flow rates.

6. Plug Valve

• Description: Depending on the design, some plug valves may have a port that is smaller than the pipe diameter.
• Use: Commonly used for on/off control in various industrial applications.

7. Pinch Valve

• Description: The flow is controlled by pinching a flexible sleeve or bladder, which creates a reduced area for the fluid to flow through.
• Use: Best for slurries and fluids containing solids, allowing for easy control and isolation.

8. Diaphragm Valve

• Description: Not all diaphragm valves yield a full bore, particularly in tube-type designs.
• Use: Suitable for handling corrosive fluids, slurries, and applications requiring tight shut-off.

Summary

Understanding the type of valve and its design is crucial for ensuring the performance meets the specific flow requirements of an application. Reduced bore valves, while advantageous in some cases, may lead to increased pressure drops and reduced flow rates compared to full bore options.