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Showing posts from March, 2023


Submersible pumps are commonly used in various industries such as construction, mining, wastewater treatment, agriculture, and general manufacturing. Typically, these pumps consist of a vertical electric drive motor that is directly connected to the impeller, and they are designed to operate for long periods with minimal maintenance. BEARING ARRANGEMENT The bottom bearing, also known as the locating bearing, usually consists of a double-row angular contact ball bearing or a pair of angular contact bearings, which are responsible for supporting the axial and radial loads generated by the pumped fluid. Since the bearing is subjected to heavy loads, it is important to select the appropriate bearing to achieve the desired service life. On the other hand, the top free bearing is generally a deep groove ball bearing that takes a light radial load. Typically, C3 clearance is used to compensate for the reduction in clearance caused by the heat generated by the electric motor. CREEP PHENOME

Why Pump Shafts Often Break at the Keyway Area

By NTS Pump shaft failure can lead to significant downtime and repair costs in industrial plants. One of the most common locations for pump shaft failure is at the keyway area. In this article, we will explore the reasons why pump shafts often break at the keyway and what can be done to prevent such failures. The keyway is a high-stress point (weakest point)  on the shaft, where a key is inserted to transmit torque between the shaft and the pump impeller or coupling. During operation, the keyway experiences cyclic loading that creates a bending moment in the shaft, which is concentrated in the keyway area. Over time, this cyclic loading can cause fatigue failure in the shaft material, leading to a fracture at the keyway. In addition to cyclic loading, other factors can contribute to shaft failure at the keyway. Improper keyway design or installation can lead to stress concentrations or inadequate clearance between the key and keyway . Misalignment or overloading can also cause excess

Pump Shaft Breakage: Case Studies and Solutions

By NTS Pump shaft breakage is a common issue that can cause costly downtime and repairs in various industries. In this article, we will explore several case studies of pump shaft breakage and the solutions implemented to prevent future failures. Case Study 1: Chemical Processing Plant A chemical processing plant experienced repeated pump shaft breakages in their cooling water pumps. Investigation revealed that the pumps were not properly aligned with the motor and had excessive vibration due to the misalignment. This caused the pump shaft to fatigue and break over time. The problem was resolved by realigning the pumps and installing vibration monitoring equipment to detect any future misalignment or excessive vibration. Case Study 2: Wastewater Treatment Plant A wastewater treatment plant had issues with pump shaft breakage in their sludge pumps. The pumps were designed with a straight shaft and lacked a flexible coupling, causing excessive stress and vibration on the pump sha