Cavitation in a High Pressure Dredge Hose

If cavitation were to happen in a high pressure hose of a dredge the big mass of compressed air would alternately fall and come back as one or more little masses so many times per minute that it would not even be seen. What would happen is that you would be able to see the little bubbles that would be moving down the current flow quick quickly. This is pretty frequent inside the high pressure hose when the flow is just beginning. So when you are doing the first inspection on a dredge pressure hose, make certain to look for turbulence and quickly moving bubbles. They should go away almost entirely within the first ten to twenty seconds of operation. One option is to use clear plastic material so that it is able to get checked visually; when the high pressure hose is working the right way it should look like it is full of water but should not show that it is moving a tremendous amount. If you squeeze it in between your fingers it should give you a lot of resistance and should not fold. If you notice there is a lack of resistance, it is most likely sucking up gases. In order to resolve this setback you should first check the clamp of the intake hose to make sure that it is on tight enough. If you are not sure, you can put your hand in the water and trickle some water on the area of the clamp. If you see that the water is sucked in, then you know that the trouble is that the pump is in taking air and tightening the clamp should resolve problem. If this is not the problem or does not work, try running your hand over the area of the suction tube on top of the surface of the water in order to check if it has a leak. One last thing is to check the position of the foot valve and strainer. It could be that the strainer has moved to an area where there is underwater turbulence and cavitation that cannot be seen from the top. If this does come about, it is possible that vaporized water is being sucked into the pump where it will not only slow down the speed of the pump but will also damage the impellers and covering as well. To take care of this problem, simply move the strainer to a different more peaceful section of the stream.