Hydraulic cylinders are of two types – single-acting cylinder and double acting A single-acting hydraulic cylinder is that type of cylinder in which the working fluid only acts on a single side of a piston but in the case of a double-acting hydraulic cylinder the working fuel can act on both sides of the piston. Hydraulic cylinder is highly essential for making the difficult tasks and they can provide force especially with a Hydraulic Lifting Jack for making shapes in machinery.
Reason to bleed a double-acting hydraulic cylinder
There are various reasons for which it becomes necessary to bleed the double-acting hydraulic cylinder and some of the essential reason are listed as follows:
- Sometimes there may be an issue in the pockets of the hydraulic cylinder for which the air that enters the hydraulic cylinder will not be able to work as efficiently as it should be. Due to this problem, it sometimes becomes necessary to bleed the double-acting hydraulic cylinder. If you do not bleed the double-acting hydraulic cylinder from time to time it may lead to the failure of the catastrophic system of the cylinder.
- The air may enter the hydraulic system through the hydraulic pump. When the air enters the double-acting hydraulic cylinder it contaminates the hydraulic fluid that can cause cavitation or aeration.
How cavitation and aeration can damage your double-acting hydraulic cylinder?
Cavitation is a process that mainly occurs when there is a rapid change of pressure in the liquid such as hydraulic fluid. Due to this, small vapor-filled cavities are formed in those areas where the pressure is measured to be the lowest. The bubbles will be imploded at the time when compression will happen in the hydraulic cylinder. This will lead to metal erosion which may slowly damage the components that are inside the double-acting hydraulic cylinder. The erosion is the main reason for damaging the components that are there inside the hydraulic system. For example, the metal seals of the double-acting hydraulic cylinder may get damaged due to this erosion.
Apart from that, the erosion may further contaminate the fluid of the hydraulic cylinder due to which more damage occurs to the moving components. Hence, because of all these reasons, the double-acting hydraulic cylinder may fail.
Aeration occurs at the time when the air leaks into the double-acting hydraulic cylinder and the hydraulic fluid gets dissolved. This has mainly occurred through the pump seal or pipe fittings. Due to the degradation of hydraulic fluid, the wear and tear of other components get accelerated since during that time the oil cannot provide the required level of lubrication. This causes overheating in the double-acting hydraulic cylinder and dieseling may occur when the hydraulic fluid mixes with the air which may result in an explosion when there is an explosion in the hydraulic cylinder.
When do you need to bleed a double-acting hydraulic cylinder?
By bleeding you will be able to let the air escape that has not yet mixed with the hydraulic fluid. But it should be done very carefully. You should bleed the double-acting hydraulic cylinder only during the following stage:
- Noise: When you will observe that there is a bang or knocking noise in the hydraulic system you must know that the air is trapped in the hydraulic cylinder and it is the perfect time to bleed the cylinder. Due to the air compressing and decompressing the noise is heard in the hydraulic system. Hence, during that time it is very essential to inspect the hydraulic cylinder and pump. While bleeding you must make sure to check the seals as well as inspect the hydraulic fluid.
- Before the installation: Before you install your double-acting hydraulic cylinder it is necessary to bleed the cylinder. This is because the air that may get trapped in the cylinder will act as a gas shock absorber due to which the cylinder may let the air escape with a breather valve that exists at the top. Again when the new double-acting hydraulic cylinder will be tested you must check the trapped air pockets since many times it causes the seal to blow out from the cylinder housing.
Ways to bleed the double-acting hydraulic cylinder
There are various methods to bleed the double-acting hydraulic cylinder. However, in this article, we have come up with some essential tips that are mostly used to bleed a double-acting hydraulic cylinder. The following are those steps that you must follow while bleeding the double-acting hydraulic cylinder:
- The first thing that you need to do is to gather all kinds of supplies and tools that you need to disassemble the hydraulic system. But while you do it make sure that the hydraulic fluid is cleaned properly. Apart from that, you must also clean the empty bottle.
- It is also essential to work on an even surface while bleeding a double-acting hydraulic cylinder since it makes the air bleed easily.
- You also need to remove all those parts of the double-acting hydraulic cylinder that can make the hydraulic line possible.
- Whenever you will bleed the double-acting hydraulic cylinder make sure that you are at the farthest away from the hydraulic pump first.
- You must bleed that line at last which is closest to the pump. Again you must also make sure that you bleed only one line at a time.
- You should also make sure that the hydraulic fluid reservoir is filled. When a double-acting hydraulic cylinder runs dry more air will fill the hydraulic system. Again you will also be required to restart the process from the beginning.
- You must also extend the cylinder completely and also leave its position for a few minutes that will also allow the air to rise naturally. The time that will be required for bleeding the double-acting hydraulic cylinder depends on the air in the cylinder.
This is how you can bleed the double-acting hydraulic cylinder which is highly essential to maintain the useful life and bleeding the cylinder will also help to maintain the operating efficiency of the machine.