14-09-2023

Improved process efficiency with high-performance butterfly valves

Process efficiency can be defined as optimal flow capacity, minimized emission and leakage, and low energy consumption. At the same time, the first two contribute to the last – but not least: low energy consumption.

Improving process efficiency through lower energy consumption
The newest and most modern Neles™ Neldisc™ butterfly valves enable significant advances in lower energy consumption compared to traditional valve designs. These improvements have been achieved through various innovative features.

First, optimized geometry based on field-proven technology and decades of experience​ ensures smooth and efficient flow through the valve. These valves are designed to minimize turbulence and pressure drop. The flow resistance caused by the valve is thus reduced, and less energy is required to overcome the resistance, resulting in reduced energy consumption. An optimized disc design and backflash-free disc-shaft connection provide precise flow control. Precise control minimizes unnecessary pressure fluctuations and repetitive readjustments, resulting in energy savings.

Furthermore, reduced torque requirements for the tight shut-off of the modern butterfly valve allow the use of smaller actuators. The smaller the actuator, the lower the energy consumption. Compressed air systems especially can be very energy wasting – and sometimes the biggest energy consumers in the whole factory.

Additionally, the butterfly valve’s reliable performance is ensured with unique metal seat technology . A very tight sealing effect is achieved with careful material selection, the triple offset design, and many of the other smart design choices that help minimize leakage. By reducing and even eliminating leaks, these butterfly valves improve the overall system efficiency and minimize energy losses. Minimizing both internal and external leakages, as well as the risk of failure in demanding service, also makes these butterfly valves sustainable choices.

Improving process efficiency through optimal flow capacity
When considering butterfly valve flow capacity, an important fact needs to be faced: The disc – the heart and soul of the butterfly valve – is always there. Even when the valve is fully open, the disc stands there in the middle. This means disc design is once again playing a key role: It allows the smooth passage of the process medium with minimal turbulence, and gives as much free space for the flow as possible in the fully open position.

In addition to a robust through-shaft version, we have designed a high-flow capacity version. With this two-shaft version, where the shaft is divided into a separate drive shaft and trunnion, the butterfly valve’s flow capacity is optimized, leaving even more free space in the middle of the valve flow port. The two-shaft design is not a compromise but a real option for the highest possible flow capacity. Both one-shaft and two-shaft options have the same strength – the only real difference is in flow capacity.

It is worth noting that a butterfly valve’s flow capacity can be further optimized by selecting the appropriate valve size. The latest version of Nelprof, the state-of-the art online valve sizing tool, can be used to calculate the correct size. In sizing, the effects of various process parameters such as pressure, temperature and flow media characteristics need careful consideration.

Sari Saxholm
Product Manager, Butterfly Valves