Hydraulic seal functions essentially in almost all hydraulic applications. The most crucial role, however, is to prevent fluid leakage while resisting extreme temperatures, high pressures, and transversal forces. To select the best seal kits, here is a brief introduction to hydraulic seals.

What is hydraulic seal used for?

A hydraulic seal, first of all, is to contain the fluids and maintain the hydraulic pressure (piston seal, stem seal, anti-extrusion ring), to stop the intrusions of impurities. Besides, it is to keep the lubricating film on the rod (wiper seal), resist deformation under radial load by guiding the piston and the rod (guide ring, guide strip).

A hydraulic seal is to seal in fluid and block the flow towards the piston. Therefore the pressure will build-up on one side of the piston. We can get to know how it fulfills this job from each part of a hydraulic cylinder. The hydraulic seals are external seals that prevent cylinder leakage. Guide rings serve to guide both the piston rod and the piston in the cylinder so that no metal-to-metal contact occurs. The task of the scraper is to keep harmful contaminants away from the cylinder and thus avoid cylinder damage.

Hydraulic seals used in numerous applications, such as off-highway vehicles, machine tools, trucks, and injection molding machines, must be suitable for their intended use and environment.

The most common type of hydraulic seal

O-ring is the most common type of hydraulic seal that is suitable for both dynamic and static applications. This type of seals are heat resistant, compatible with silicone petroleum-based fluids and are also widely used in hydraulic fluid applications as well as non-aromatic liquid products and solvents.

Examples of O-ring mounting

Piston type (dynamic): placed in a groove around a cylinder that slides in a chamber the seal undergoes a radial compression.

Cover type (static): placed in a flange groove, compressed by a solid pad.

This seal must correspond perfectly to the dimensions of the groove for which it was chosen. It is found in metric and imperial dimensions.

How to avoid seal damage in hydraulic applications 

Different requirements apply to the printing for multiple applications. When it comes to choosing the right seal, the pressure limit for the application must be clearly known. With regard to the printing requirements of the machines, the first factor to be considered is the necessary pressure unit Megapascal (MPa). Without reliable, high-quality parts, the cylinder can only deliver inferior performance, not to mention the shorter life. That’s why the hardware is so crucial to the function of a hydraulic system. As a rule of thumb in choosing a seal: the better the hardware, the better the seal.

The design of the components will significantly affect the choice of a seal. The decision to design is made by considering the necessary speed, efficiency, and compliance with standards and reliability. Knowledge of the mounting dimensions assists in the selection process of the seal.

hydraulic applications

Essential things to consider in choosing the seal kits

In terms of the stress on the seals in hydraulic applications, selecting the right seal for a particular application is particularly important to prevent damage. To choose it, take the inner dimension of the throat and its width. If there is no groove, lay the seal flat, check if it is concentric and raise the ribs with a caliper. The following questions are helpful in choosing the seal to avoid future seal damage:

Is the seal resistant to the contamination?

Is the seal friction-free?

Can the seal be easily assembled?

Is the seal easy to maintain?

How does the seal behave at extreme temperatures and in materials?

Do the gaskets comply with industry standards?

Taking a long look at hydraulic seals can reduce the probability of damage later! Since the seal ring shall be fully fitted to other parts, the seal kits that contain different types will be more useful. YBAS Boom CYL Seal Kit includes a full range of mold size for Arm Bucket of the Excavator. Not only do they have a strong resistance to high pressure and temperature, but also they are not easy to expand for a long time. With the high performance recognized by customers all over the world, it saves your worry about the safety issues that the wrong seals may bring.

If you haven’ t decided which to buy yet, you may find your ideal hydraulic seal from YBAS. As one of the most professional seal manufacturers in China, YBAS provides high quality sealing products widely used in supporting and maintenance. Hydraulic seals for various excavators and hammer breaker machine can be found here, all of the high quality and best resistance.


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