Butterfly valves are not automatically full port valves. They can either be a full port butterfly valve (full bore), or a reduced port valve. This would depend on the design and manufacturer.
Different applications require different valve types. In this case, deciding between a full port vs standard port relies on significant factors. These factors are pressure drop, size and weight, cost, and application based on process medium.
This article discusses the differences between a full port and a reduced port valve. It will also guide you on how to choose the right valve types for an industrial project.
What is a Full Port Butterfly Valve?
A full port valve has an internal bore that matches the inside diameter of the connected pipe. When the disc is fully open, fluid flows freely. That’s why these valves are recommended in applications that require rapid flow control.
Differentiating a Reduced Port Butterfly Valve
A reduced port, or standard port, valve, has a smaller internal bore than the pipe it connects to. The difference in size causes a pressure drop as fluid passes through. This requires more pump energy to maintain the same flow rate. This valve offers cost and weight savings for non-critical systems.
What are the Key Differences between Full Port vs Standard Port Valves?
The differences between these two valves are measured by flow area, pressure drop, size and weight, cost, and application.
The first factor is flow efficiency. Standard port valves reduce flow the most because they create a bottleneck. On the other hand a full port design can deliver 30 to 50% higher flow coefficients (Kv) at the same pressure drop. This results in more throughput without adding pump capacity.
Another factor is pressure loss. Reduced port valves create two to four times more pressure drop. This increases energy costs, especially in a 24/7 operation.
Full port butterfly valves are larger, with a heavier body and disc. Reduced port designs are more compact and cost 15 to 25% cheaper upfront. Reduced port valves are specified in space-constrained skin installations or low-criticality services.
Standard port valves have easier actuation. Their lighter, smaller intervals require less operating torques and smaller actuators. This makes manual or compact pneumatic operation more practical.
Pigging compatibility is only for full port valve designs. Choose full-port valves if you need to run inspection or cleaning pigs through your pipeline.
This table summarizes the key differences:
| Feature | Full Port (Full Bore) | Reduced Port (Standard) |
| Bore Diameter | Matches internal pipe diameter | Smaller than pipe diameter |
| Pressure Drop (ΔP) | Negligible; optimized flow | Significant; creates turbulence |
| Pigging Ability | Compatible with cleaning pigs | Non-compatible |
| Typical Standards | API 609 / ISO 5752 | General Commercial |
| Best Use Case | Oil & Gas, Slurry, High-Flow | HVAC, Compressed Air |
Case Study: Switching to Full Port in a Water Treatment Plant
A municipal water facility saw electricity costs climb while running its DN200 pipelines 24/7. The problem was that the standard port butterfly valves throughout the system were generating excessive pressure drop. This resulted in increased pumping energy.
The facility cut down on pump energy consumption when they replaced the critical inline valves with full port designs. That change reduced annual operating costs and extended pump service life. This is a clear example of how the full port vs. standard port decision reaches well beyond the valve purchase price.
Conclusion
Triple offset butterfly valves (TOVs) rated for ASME Class 300 or Class 600 pressure service deliver full-port performance. Unlike basic concentric designs, these engineered offsets utilize a camming action to minimize seat wear, overcoming the flow restrictions and pressure limitations found in standard resilient-seated valves.
Choose a full port configuration to minimize pressure loss, support, pigging, and reduce energy costs. This applies in critical applications such as oil, gas, or water treatment facilities. For lower stakes environments such as HVAC or compressed air, standard port valves are a cost-effective, space-saving solution.
Since 1985, CTGV has leveraged its 66,000 sqm facility and 20,000-ton annual capacity to manufacture over 80 valve types.
CTGV provides factory-direct expertise to help you choose between engineered full-port valves for maximum throughput or standard configurations for general service. Consult our engineering team for ISO-certified valve specifications tailored to your pipeline’s flow requirements.
