Reference value for the vertical deviation of machine pump couplings under high-temperature operation
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Dear experts, when aligning the couplings between the motors of pump equipment that operate at high temperatures and the equipment itself, should there be a difference between the upper and lower parts (that is, between the high-temperature end and the low-temperature end)? Is there any standard for this? What is the approximate allowable standard deviation? Q
Our usual practice is to have the motor 0.15 mm higher than the pump when it’s at room temperature, or simply align them with zero offset to zero offset, as the compensation capability of the diaphragm coupling is more than sufficient
It can be calculated based on the actual measured temperature and the expansion amount of the equipment material
For high-temperature pumps, first, the expansion amount can be calculated based on the temperature rise at the support points in order to draw the cold-state curve; second, after the pump is stopped and in its hot state, the concentricity is checked again, and this check is performed once the pump has fully cooled down. By comparing the results before and after, the cold-state curve can be determined. This method is the most accurate.
High-temperature pumps, especially large ones, must be re-aligned a second time after being warmed up in order for this to be effective.
There is definitely a value for thermal expansion; it varies from device to device, and generally the equipment manufacturer will inform you of it