12/18/2023 0 Comments Submerge pumpReliability-focused pump users employ this state-of-art laser optic alignment determination method, even though it is somewhat more complicated to set up, but it can be more accurate if properly used. The advantages of modern laser-optic alignment devices far outweigh the possible initial cost advantages of other, more conventional methods. This state-of-the-art system emits a pulsating non-hazardous laser beam that automatically determines relative shaft positions and conveys this information to its microprocessor. Although better then the "straight edge and feeler gauge method", the dial indicator method does have a few shortcomings, such as: You can then use mathematical formulas to calculate shim changes to correctly align the unit. The Reverse Indicator Method uses a dial indicator on the pump shaft to read the motor shaft, and a dial indicator on the motor shaft to read the pump shaft. You can then calculate shim changes for the motor feet to correctly align the unit. The Single Indicator Method uses a single dial indicator to take both the rim and face reading. There are two basic dial indicator methods. It is more difficult to attain the equipment manufacturer's alignment specifications through the use of a straight edge and feeler gauges. Shim changes are estimated and the alignment is attained through a process of trial & error. The straight edge is laid across the flanges of the coupling hub and the feeler gauges are used between the faces of the coupling hubs. Used primarily for very small pump / motor combinations where there is not enough room to use more accurate but larger alignment methods. This is the easiest and least expensive method of doing alignment but it is also the least accurate. Figure 1 shows the best alignment that can expect from the three most prevalent alignment methods practiced in the industrial, worldwide. Where to make shimming adjustments (Align the motor to the pump by shimming the motor feet)Īlignment accuracy is critical to pump and driver longevity as stated above, and generally the better the alignment the longer the pump and driver bearing life.Alignment equipment sag (with dial indicators).These conditions are described at the location of the coupling, because it is here that harmful machinery vibration is created whenever misalignment exists.īasic issues that must be taken into account regarding pump alignment are: Thus, we end up with four specific conditions of misalignment, traditionally called Vertical Offset, Vertical Angularity, Horizontal Offset, and Horizontal Angularity. It has been found to be most convenient to break this three-dimensional space up into two planes, the vertical and the horizontal and to describe the specific amount of offset and angularity that exists in each of these planes simultaneously, at the location of the coupling. Pump shafts exist in three-dimensional space and misalignments can exist in any direction. Excessive pump vibration can shorten bearing and mechanical seal life. Harmful machinery vibration is created whenever misalignment exists. Pump and driver bearing overload, leading to failure or short bearing life.Extreme wear in gear couplings and component fatigue in dry element couplings. Coupling overheating and resulting component degradation.Hundreds of technical articles and presentations have elaborated on the serious problems that are caused by incorrect alignment between the pump and driver, such as: Periodically, as a preventive maintenance check of the alignment, following the plant operating procedures for scheduled checks or maintenance.Changes have been made to the piping system.The process operating temperature of the unit has changed.A pump and drive unit are initially installed (before grouting the baseplate, after grouting the baseplate, after connecting the piping, and after the first run).Reduced parts expense and lower inventory requirementsįurther, in order to insure good alignment, the alignment must be checked and correctly set when:.Increased productivity through time savings and repair avoidance.Lower energy losses due to friction and vibration.Good alignment has been demonstrated to lead to: Indeed, using precise alignment methods is one of the principal attributes of a reliability focused organization. Performing precise alignment, therefore, pays back through preventing the costly consequences of poor alignment. The inevitable result is premature failure of shaft seals and bearings. Even small pumps can generate big losses when shaft misalignment imposes reaction forces on shafts, even if the flexible coupling suffers no immediate damage. Misaligned pumps can even consume up to 15% more energy input than well-aligned pumps. Experience shows that many pump distress events (failures) have their root cause in the misalignment of the pump to motor.
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