Why telescopic not rigid connection will be deformed and elongated in double suction in open cycle pump displacement, for the non hydraulic machinery of professional personnel, and sometimes is difficult to understand, so in order to be able to have a perceptual awareness, before the pump drive operation, in the rubber expansion joint on the right side of the flange placed a dial indicator measuring flange is to the right. After the OK indicator that drive saw the dial indicator pointer rotation of the two laps, look carefully, hit the table to the right place displacement the 2.1mm. Because the rubber expansion joints due to not rigid connection, diameter of phi 700 rubber tube, in under the action of water pressure 0.6MPa, the axial tension of 23t (tension F=0.6 x 10.2 * pi * 702/4=23553kg hundredth of 23t), rubber pipe Bigang tolerance, not so much the tension, so the force will transfer to the pump body, the double suction pump displacement. After stopping the pump check the coupling of the neutral, the horizontal direction of the dislocation of up to 0.2mm. If in operation, the dislocation will be even greater. Imagine the pump shaft center dislocation so large, vibration is poor and easy to damage the bearing inevitable phenomenon in running.
Some people believe that: there is not a rubber section will be displaced, the use of rubber section is not caused by pump vibration and bearing the root causes of damage. There are two factors can make the pump displacement small: A is the rubber section in the installation has been in tension, and elongated room is relatively small; another pipeline left room for elongation, force stretched rubber Festival is to the left and right sides of the elongated, which side is easy to move is moved to which side, pump rubber Festival stretched, is likely to to shift to the left a little more, pump, although less mobile, but certainly also on the top of a thrust, for double suction impeller pump operation stability also certain influence. So later when the other three pump rubber section to rigid connection, double suction in the open cycle pump bearing temperature rise and amplitude values significantly worse than the other three.
Although the rigid or flexible takeover does not become double suction in open cycle pump damage to the root cause, but in any case it is a potential problem, so the rigidity pipe replacement flexible the takeover, with short replaces the original expansion joint, circulating pump tire section with 12 long on bolt fixed in order to strengthen the stiffness.
