What are the most common seals used in hydraulics?
Hydraulic cylinders play a vital role in various situations and applications daily. Whether it’s a plow truck clearing roads, a utility vehicle addressing electrical issues, or a compactor at a local recycling center, hydraulic cylinders are in constant motion.
However, there’s more to Automotive Lift Repair Orlando hydraulic cylinders than meets the eye. To effectively contain the pressurized fluids within a hydraulic cylinder system and facilitate movement, a sophisticated arrangement of high-performance seals is necessary, divided into two primary categories: (1) static seals and (2) dynamic seals (along with guide rings).
Our Common Seals Used in Hydraulics
Let’s take a closer look at some specific seal types within each category.
Static Seals: These seals do not experience any movement when pressurized. Examples include O-rings, D-rings, backup rings, cover seals, and gaskets. A prime example of a static seal is the O-ring, known for its versatility and availability in various sizes. When installed in the cylinder housing and compressed by a casing, the O-ring forms a physical barrier between the housing and the casing. O-rings are often used with backup rings for pressures exceeding 1500 p.s.i. Made from materials like nitrile rubber (NBR), fluoro rubber (FKM), and ethylene propylene diene (EPDM), they are compatible with a wide range of mineral oils, water-based fluids, and air. Other materials, such as polyurethane (TPU) and silicone, can also be effective in static applications.
Automotive Lift Repair Orlando Dynamic Seals: These seals experience axial and/or radial movement when pressurized. This category includes piston seals, rod seals, rotating seals, wipers/scrapers, and oil seals.Rod seals maintain pressure in the cylinder by preventing fluid from escaping. Leakage from the rod seal can hinder equipment performance and potentially cause environmental issues. Wipers, also referred to as scrapers, block contaminants like dirt, dust, and moisture from entering the cylinder as they retract into the system. Contamination can lead to significant damage to the rod, cylinder wall, seals, and other components, often resulting in premature seal and component failure in fluid power systems.
Guide Rings: Composed of resin-bonded fabric, guide tape, and engineered plastics, guide rings help align the piston in the cylinder bore and the rod in the cylinder head of a hydraulic cylinder. They protect against damage from side loading by preventing metallic contact between axial and rotational components.
Selecting the right seal is essential for ensuring optimal performance in hydraulic cylinder applications.
There are six primary types of seals commonly found in hydraulic cylinders:
The main function of an Automotive Lift Repair Orlando Wiper Seal in a cylinder is to prevent dirt and other contaminants from entering the system. This is typically achieved through a wiping lip that faces outward from the cylinder.
Piston Seals are designed to create a seal between the piston and the cylinder, allowing for dynamic pressure that enables the cylinder to extend and retract.
Rod Seals are intended to seal the gap between the rod and the gland.
As their name implies, Rotary Seals are used to seal against a dynamic, rotating surface.
Static Seals encompass a variety of seals that create a seal against static surfaces only.
Automotive Lift Repair Orlando Guide Rings serve to prevent contact between two moving surfaces.
Seals can be classified as either single or double acting. A single acting seal is designed to handle pressure from one side only, while a double acting seal can manage pressure from both sides.
To accommodate the various applications available, sealing products come in both metric and imperial sizes and are made from a wide range of standard and specialized materials.
Not all seals are readily available off the shelf; some may need to be custom manufactured to meet the specific requirements of an existing application or for a new design.
Choosing the appropriate hydraulic seals requires careful consideration of various factors to ensure effective sealing performance and compatibility with your hydraulic system. Here are some steps to help guide you in the selection process:
Identify the Application:r Start by determining the specific application and operating conditions for the hydraulic seals. Take into account factors such as pressure, temperature, speed, media compatibility (the type of fluid in the hydraulic system), and any potential exposure to chemicals or abrasive materials.
Understand Automotive Lift Repair Orlando Seal Types: Familiarize yourself with the various types of hydraulic seals available, including piston seals, rod seals, wiper seals, and O-ring seals. Each type has distinct features and designs tailored to specific sealing needs. Research the benefits and limitations of each to find the one that best fits your application.
Material Selection: Hydraulic seals are constructed from different materials, such as rubber, polyurethane, and PTFE (polytetrafluoroethylene). Assess the compatibility of the seal material with the hydraulic fluid, as some materials may not perform well with certain fluids or at specific temperatures. Additionally, evaluate the material’s resistance to wear, abrasion, and chemical exposure.
Size and Dimension:Determine the necessary size and dimensions of the hydraulic seal based on the equipment specifications and sealing requirements. Consider factors like rod diameter, bore diameter, seal height, and groove dimensions to ensure a proper fit and effective sealing performance.
Consult Automotive Lift Repair Orlando Manufacturer Guidelines: Refer to the manufacturer’s guidelines and recommendations for seal selection. Manufacturers typically provide technical specifications, compatibility charts, and performance data for their hydraulic seals. Use this information to select seals that align with your application’s specific needs.
6. Performance Expectations: Consider the desired performance characteristics of the hydraulic seals, such as leakage prevention, pressure resistance, temperature tolerance, and lifespan. Choose seals designed to meet or exceed your performance criteria.
7. Seek Expert Advice: If you’re uncertain about which hydraulic seals to select, consult experts or suppliers specializing in hydraulic sealing systems. They can offer valuable insights, recommendations, and technical support based on their expertise and understanding of hydraulic seal applications.
8. Automotive Lift Repair Orlando Testing and Evaluation: Consider conducting tests or pilot installations to assess the performance of the chosen hydraulic seals under real-world conditions. This will help ensure their suitability and identify any potential issues or areas for improvement.