In most process applications there are two different types of valves used: on/off and control. On/off valves allow full flow or stopping flow completely. Control valves, in contrast have the ability to control the AMOUNT of flow, also known as throttling.
V-Port Ball Valves
V-Port ball valves are a specialized ball valve that offer:
- Suitability for coarse control applications
- Reliable shutoff
- Many different V-Port balls options available to accommodate different flow ranges with the same valve body, most common being 60˚, 30˚, and 15˚
Globe Valves
Globe valves use linear actuation and offer:
- More precise control due to a more linear flow curve (See Figure 3 below)
- Do not suffer uneven wear in the mid positions
- Typically have higher pressure drops than V-Port valves
However, they do not typically provide a bubble tight shutoff. They also require greater force or a larger actuator to seat the valve.
V Port Ball Valve and Globe Valve Comparison
| V Port Valve | Globe Valve | |
|---|---|---|
| Function | 2-way flow control | 2-way flow control, 3-way mixing, 3-way diverting |
| Positive Shutoff | YES | Not leak free |
| Control Capability | Coarse | Fine |
| High Duty Cycle | NO | YES (constant) |
| Flow Capacity | Higher | Lower |
| Cavitation Prevention | — | |
| High Temperature | — | Preferred |
| Ease of Maintenance | — | Preferred |
| Cost | More economical | — |
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