Hydraulic cylinders have got a large number of applications, particularly in the construction industry. They are responsible for the functioning of some cranes and earthmoving equipment. Seals are used to prevent leakages in these systems and are perhaps one of the most important parts. However, these cylinders' seals may fail prematurely, and in most cases, it's simply due to poor maintenance practices. Here are a few ways you can minimise such failures.
Choose the right seals
You need to ensure that you're using the right seals for the job. There are different kinds of seals to suit the different applications available. If you're going to be working in aggressive environments or doing a lot of load holding, then the seal needs to have the ability to handle that pressure properly. For instance, use polyurethane seals as opposed to nitrile rubber seals when you're going to be exerting a lot of pressure on the machine (i.e. in mining).
Inspect the cylinder alignment
Misalignment is perhaps one of the most common causes of premature seal failure. The point of contact between the machine and piston rod needs to be properly aligned. Here's where the gland and seals are. Once the alignment shifts over to one side, the gland and seal would rapidly wear out on one side. A damaged seal would let contaminants into the hydraulic fluids, which eventually leads to serious damages. Check your gland and seals for any uneven wear, and take the cylinder to a hydraulic service before things get worse.
Choose the right surface finish of the rods
Another common reason for hydraulic cylinder failure is using a poor surface finish. The rod is in constant contact with the seals, so its surface needs to be just right. When the rod surface is too rough, contamination of the rod seal occurs. On the other hand, a smooth surface damages the seals due to inadequate lubrication.
Treat the rod surface frequently and opt for superior techniques such as nickel-chrome plating as opposed to hard-chrome plating.
The cylinder seals have to be well lubricated at all times. This is particularly important if you'll subject them to very fast or high cycles. Such cycles can lead to a lot of heat generation and shock loads every time the piston hits the seals. These are some of the conditions that lead to seal failure.
Go for quality lubricants preferably the ones recommended by your manufacturer. You can also go for non-lube cylinders that are designed with an effective internal lubrication system.