Weichai Lovol Classroom: Guide to Cylinder Protection

The hydraulic cylinder is like the muscle of the hydraulic system. If the cylinder is "powerful", the digging force will be large and the work efficiency will also increase accordingly. Therefore, the protection of the hydraulic cylinder must be very strict and meticulous. When the hydraulic cylinder leaves the factory, certain protective measures will be taken to extend the product life. But do you know? When storing hydraulic cylinders, it is necessary to distinguish between short-term storage (up to three months after arrival) and long-term storage (in other situations). Below, the author will introduce the protection methods for hydraulic cylinders to everyone. Let's take a look together.

The vehicle cylinder has been installed

(1) Storage conditions

The part of the piston rod extending outside the hydraulic cylinder should be wrapped with foam paper as much as possible to prevent rust. It should also be covered with waterproof paper to prevent the loss of lubricating oil when the temperature is high. In addition, the piston rod should be wrapped with cardboard as much as possible to prevent mechanical damage.

(2) Short-term storage

For short-term storage not exceeding three months, no special measures are necessary. However, general storage conditions must be met.

(3) Long-term storage

For hydraulic cylinders that are exposed for a long time and do not move, the following protective measures should be taken

It is necessary to prevent the condensation of water vapor and the presence of corrosive gases. The part of the piston rod extending out of the cylinder must be coated with protective grease (a blend of F20-1 anti-rust oil and lithium-based grease 3#) to prevent rusting. If the on-site environment is harsh, it must also be covered with waterproof paper to prevent the loss of lubricating oil and the adhesion of dust when the temperature is high.

2. Regular visual inspections should be carried out. When foreign objects are found adhering to the surface of the piston rod, they should be cleaned up in time. Meanwhile, for those stored indoors, a full-stroke operation of the entire vehicle's hydraulic cylinders should be performed at least once every two weeks. For those stored outdoors, it should be done once a week.

Accessory oil cylinder

(1) Storage conditions

1. During storage, hydraulic cylinders should not be directly affected by weather changes. They should be protected from direct sunlight and rain. The storage location must be dry and well-ventilated. It is necessary to prevent water vapor condensation and the presence of corrosive gases.

2. The part of the piston rod extending outside the hydraulic cylinder should be wrapped with foam paper as much as possible to prevent rust. It should also be covered with waterproof paper to prevent the loss of lubricating oil when the temperature is high. In addition, the piston rod should be wrapped with cardboard as much as possible to prevent mechanical damage.

Note: It is strictly prohibited to store or place the hydraulic cylinder when the oil port plug is removed or the residual oil in the cylinder is drained.

(2) Short-term storage

After the hydraulic cylinder has been verified at the factory, 10% mixed anti-rust oil has been added to the cylinder body. Therefore, there is no need to take special measures for short-term storage not exceeding three months. However, the general storage conditions must be met.

(3) Long-term storage

For oil cylinders that have been stored for a long time without being installed (with inventory exceeding three months), in addition to short-term storage measures, the following measures also need to be added:

The cylinder must be filled with 100% of its volume of hydraulic oil.

2. The cleanliness of the medium must meet NAS8 grade.

3. Rotate the oil cylinder half a turn every two months to prevent the sealing parts from sticking together.

In addition, unprotected parts, such as assembly surfaces, machined surfaces and spherical plain bearings, etc., must all be protected with special anti-rust oil.

Availability verification

If the hydraulic cylinder has been stored for more than one year or the actual storage conditions fail to meet the requirements given in the previous section, a comprehensive inspection of its availability must be conducted before it is put into use, and functional tests must be used to confirm this.

These functional tests include:

Pressurize to 3MPa for 10 minutes to check if there is any leakage inside or outside.

◆ More than 50 times of extension and retraction movements of the hydraulic cylinder.

That's all for this issue of Weichai Lovol Classroom. Have you learned it?