Various hydraulic seal varieties, their adaptations, and the materials employed

Numerous hydraulic seal types are available, spanning a range of shapes and dimensions. Selecting the appropriate seal is crucial, as they play a vital role in facilitating the conversion of fluid power into linear motion.

Every seal type is meticulously crafted to address various factors including cylinder speeds, temperatures, pressures, and specific applications. Positioned within a cylinder or piston groove, these seals establish a barrier that effectively prevents hydraulic system leakage, thereby ensuring proper machinery function and safe operation.

TYPE 1: Piston Seals

Piston seals are dynamic hydraulic seals employed to halt the passage of fluid beyond the piston as system pressure propels the piston down the cylinder.

Key variations in piston seals include:

Single-acting: These seals only need to obstruct pressure from one side of the piston, retaining the pressure that propels the piston along the cylinder. They keep fluid on their surface, thereby reducing both friction and wear.

Double-acting: In contrast, these seals necessitate pressure from both sides to propel the piston along the bore. To effectively seal them, a double-acting seal capable of withstanding dynamic pressure from both sides is required.

Occasionally, however, two single-acting seals can be arranged in a ‘back to back’ configuration to create a double-acting seal system.

Car Lift Repair Orlando Rod Seals

Rod seals play a critical role in maintaining hydraulic system efficiency, tasked with both preventing fluid leakage from within a hydraulic cylinder and shielding it from external contaminants such as dirt.

Static seals installed directly into the housing or glands of a system, rod seals are engineered to provide dynamic sealing pressure while the piston rod is in motion.

Key types of rod seals include:

Car Lift Repair Orlando RFD Rod Seals

Also referred to as Single Acting Split Housing, these robust seals feature an anti-extrusion ring for enhanced protection. Crafted from rubberized fabric, they are easily installed in the housing to reduce friction and wear, ensuring applications remain securely sealed against fluid leakages.

RTA Rod Seals

These Single Acting seals are employed in hydraulic cylinders with limited groove dimensions. Integrated into small housings, RTA seals, combined with an NBR O-ring and PTFE inner, offer maximum sealing resistance, even under high pressure.

Car Lift Repair Orlando RUB Rod Seals

Designed for sealing piston rods, these Single Acting seals incorporate an additional O-ring profile for lubrication and abrasion resistance. Polyurethane RUB seals are particularly effective, boasting a 300 BAR resistance suitable for high-pressure systems.

Car Lift Repair Orlando TYPE 3: Wiper Seals

Also known as scraper seals, wiper seals are often used in conjunction with other sealing components to allow a ram rod to pass through the inner bore of a seal while preventing leakage.

Wiper seals are crucial for safeguarding hydraulic operating systems from external contaminants. 

Failure to secure or maintain wiper seals can result in component failure within a fluid power system, leaving other operational elements vulnerable to serious damage.

Key types of Car Lift Repair Orlando wiper seals include:

WRB Wiper Seals

These Medium Duty scraper seals aid in preventing moisture and dirt accumulation on the rod. Crafted from an NBR compound, they are directly inserted into a grooved housing.

Car Lift Repair OrlandoWRC Wiper Seals

Featuring a lip but not extending beyond the cylinder cover, WRC seals are utilized in Medium Duty applications and can be installed into a simple groove design.

Car Lift Repair OrlandoWCA Wiper Seals

With a corrosion-resistant metal ring surrounding the NBR seal, these Heavy Duty seals track the rod’s lateral movement to keep it free from heavily deposited dirt.

Most wiper seals are made from polyurethane and feature a secondary lip to catch any oil that has passed the main seal. This secondary lip can also scrape contaminants from the rod surface, earning them the moniker “double-edged wiper seals”.

Guide rings serve the purpose of preventing friction between two dynamic surfaces within a hydraulic system.

These replaceable rings, also known as Wearing Rings, are affixed to the impeller and/or the pump casing to maintain a slight running clearance between the impeller and the pump casing, thus avoiding wear on either material.

Guide rings are fabricated from various materials including:




Fabric-reinforced Phenolic Resin

Fabric-reinforced Polyester Resin

Glass-Fibre reinforced Polyacetal

Guide, or Wear, rings find application in both piston and rod setups, with common styles including butt cut, angle cut, and step cut.

Materials for Hydraulic Seals

To optimize durability and performance in specific applications, hydraulic seals are manufactured using a diverse array of materials, each possessing distinct properties.

Considering factors such as operating temperature, chemical interactions, pressure, and fluid types, materials are selected to suit each environment most effectively.

The Significance of Appropriate Seals in Hydraulic Systems

Gaskets and O-ring seals stand as indispensable elements for the success of hydraulic applications. Without these components, the operation of high-pressure systems would be unattainable.

Determining the correct seal, material, and durability requirement fundamentally hinges upon the specific application at hand. Since each hydraulic application necessitates specific sealing attributes, such as gas permeability or chemical resistance, the selection of the suitable seal holds paramount importance. Here’s why:

1. Numerous Opportunities for Seal Failure:

Under harsh conditions, seals that are incompatible with their environment are prone to failure. To avert this, the seal must possess the ability to endure the heat or chemicals employed in the application and remain uncontaminated.

2. Heat Erosion:

Heat erosion transpires when a seal is subjected to prolonged exposure to high temperatures. This phenomenon can render the seal brittle or cause it to melt, thereby shortening its lifespan. Regular inspection for cracks in high-temperature hydraulic applications is essential to prolong the seal’s endurance.

3. Chemical Erosion:

Similar to heat erosion, chemical erosion arises from prolonged exposure to harsh chemicals, resulting in degradation of less resilient materials. Selection of an inappropriate material may render it incompatible with the chemicals employed, leading to chemical degradation of the seal due to factors like oil additives, hydrolysis, or oxidation-reduction of seal components.

4. Contamination:

Contamination from dirt and debris significantly affects seal functionality. It can lead to internal leakage and decreased efficiency in hydraulic pumps, motors, and cylinders. Furthermore, valves may lose their ability to regulate flow and pressure within the system.