Explain the purpose of the anti cav valve.

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Skiddy

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Joined
Feb 14, 2009
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162
I know it prevents cavitation of the pump but why did they put it where they did. Please explain.
 
I don't think it prevents cavitation of the pump as such because its only on certain functions, i can't remember if it was lift or tilt. The aux does not have a valve as far as I'm aware. And its only one direction. I believe it works by lowering the velocity of the oil by creating a restriction.
This is just my thoughts, nothing to back it up but i think its on the side that has pressure on it most of the time. Like when you lift a load, there is pressure on it to hold it there, but when you tilt or drop the arms fluid will return to the tank at high speed as it has a load essentially pushing it back along with the fresh oil pushing the other side of the cylinder.
As most know, cavitation is a BAD thing. It causes tiny air bubbles in the oil, you would normally think thats ok but under high pressure the bubbles implode creating a high pressure point that can pit steel surfaces.
cavitation%20bubble.jpg

See the point in the middle? that acts like a hammer smashing into the surface of whatever the fluid is in be it a cylinder, pump or motor. Multiply that by thousands or millions of bubbles over time.
This is what i have read, i have nothing to back ANY of this up. I'd like to know if anyone else has heard other things. Always ready to learn new things!
 
I don't think it prevents cavitation of the pump as such because its only on certain functions, i can't remember if it was lift or tilt. The aux does not have a valve as far as I'm aware. And its only one direction. I believe it works by lowering the velocity of the oil by creating a restriction.
This is just my thoughts, nothing to back it up but i think its on the side that has pressure on it most of the time. Like when you lift a load, there is pressure on it to hold it there, but when you tilt or drop the arms fluid will return to the tank at high speed as it has a load essentially pushing it back along with the fresh oil pushing the other side of the cylinder.
As most know, cavitation is a BAD thing. It causes tiny air bubbles in the oil, you would normally think thats ok but under high pressure the bubbles implode creating a high pressure point that can pit steel surfaces.

See the point in the middle? that acts like a hammer smashing into the surface of whatever the fluid is in be it a cylinder, pump or motor. Multiply that by thousands or millions of bubbles over time.
This is what i have read, i have nothing to back ANY of this up. I'd like to know if anyone else has heard other things. Always ready to learn new things!
Cavitation is caused when the demand for fluid is higher than the pump can supply such as when you are quickly lowering the arms with a full load in the bucket the pump can't supply enough oil to fill the suction side of the cylinder and the hydraulic fluid drops below it's vapor point and forms bubbles. The anti-cavitation valve allows oil to be drawn into the suction side of the system to prevent this.
 
Cavitation is caused when the demand for fluid is higher than the pump can supply such as when you are quickly lowering the arms with a full load in the bucket the pump can't supply enough oil to fill the suction side of the cylinder and the hydraulic fluid drops below it's vapor point and forms bubbles. The anti-cavitation valve allows oil to be drawn into the suction side of the system to prevent this.
very good explanation fellas. I am much wiser now. Ha ha. I must study my control valve now. Thanks
 
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