How to level the double diaphragm coupling of a chemical centrifugal pump ？

To level the double diaphragm coupling of a chemical centrifugal pump, it is necessary to measure the non-concentricity and non-parallelism, 

and adjust the thickness of the gasket under the motor or pump support ‌. The specific steps are as follows:

Measurement and Analysis

 tool selection ‌ :

High-precision equipment (such as dial indicators, laser aligners) : Double diaphragm couplings suitable for high-speed and rigid connections, capable of measuring radial and angular displacements. ‌

Low-precision equipment (feeler gauges, knife-shaped rulers) : Suitable for low-speed, elastic connection devices, only measuring radial deviations. 

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 Key points of measurement ‌ :

The end face of the coupling should be flat and smooth, free of rust or burrs. ‌

The anchor bolts of the motor must be fully tightened to prevent loosening and affecting the measurement. ‌

The measurement points should be evenly distributed around the circumference of the coupling (4 to 8 points) to ensure the accuracy of the data. 

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Adjustment method

 eliminate height difference (radial displacement) ‌ :

If the motor shaft is lower than the pump shaft, gaskets with a thickness of Δh should be added simultaneously under the front and rear supports of the motor to raise the motor shaft. ‌

The calculation of gasket thickness should be based on the original state and error value to ensure that the axes are parallel. ‌

 correct opening (angular displacement) ‌ :

Gaskets of different thicknesses should be added respectively under support A (front support) and support B (rear support). The thickness of the gasket on support B should be slightly greater than that on support A. ‌

Total adjusted thickness: Front support A = Δh + AC; The rear support B = Δh + BD (AC and BD are the error correction values). ‌

 empirical method combined with computational method ‌ :

Experience method: Directly add or remove gaskets based on the experience of experienced masters, and the allowance for bolt tightness needs to be taken into consideration. ‌

Calculation method: Calculate the elevation amount through the formula Δh = (e/2) × (L1/L2) (where e is the radial deviation and L1 and L2 are the support spacings). ‌

Precautions

After adjustment, the concentricity of the coupling needs to be remeasured to ensure that the error is within the allowable range (generally, the radial deviation is ≤0.05mm and the angular deviation is ≤0.02mm). ‌

Before reinstalling the protective cover, make sure all the fastening bolts are tightened to prevent loosening during operation.

If you are unable to start the newly purchased ATACH brand chemical centrifugal pump, please contact us