What is a Pelton Turbine?

The Pelton turbine is an impulse-type water turbine used in hydroelectric power generation. It is named after the American inventor Lester Allan Pelton, who invented it in the 1870s. The basic operating principle of this turbine is based on a jet of water, coming from pipes under high pressure, being shot at very high speed onto a specially designed wheel with buckets. The kinetic energy of the water striking these buckets causes the wheel to spin, and this rotational motion is transferred to a generator to be converted into electrical energy. Pelton turbines operate with extremely high efficiency, especially in geographical conditions where there is high water pressure (high hydraulic head) but low water flow (volume).

One of the most important features of Pelton turbines is their simplicity and efficiency. Thanks to the unique shape of the buckets, almost all of the water's energy is converted into rotational motion, which provides high efficiency. At MBS Balance, we know how critical the correct balancing of such turbines and their wheels is for efficient and vibration-free operation. The slightest unbalance in the turbine wheel can damage bearings, lead to energy loss, and negatively impact the system's overall performance. Therefore, balancing these critical parts is essential for safe and long-lasting operation.

The criticality of the Pelton runner from a balancing standpoint comes from its mass being concentrated in the numerous buckets placed around its circumference. Casting tolerances in the buckets, cavitation and wear (erosion) that develop over time, and repair welds change the mass distribution of the runner and create unbalance. Although static or single-plane balancing generally comes to the fore due to its disc-like geometry, two-plane dynamic balancing may be required on wide runners and at high speeds.

In hydroelectric units, unbalance directly affects the bearing load, seal wear, and the stability of the power delivered to the grid; therefore rebalancing the runner after maintenance and repair is recommended. Because large-diameter runners are difficult to remove and transport, on-site balancing is often the most practical solution. With both workshop and on-site balancing solutions for turbine runners, MBS Balance ensures long-lived and efficient operation within tolerances compliant with ISO 21940-11.