High temperature corrosion resistant skeleton oil seal: scope of application and advantages

1. Introduction

1.1 Importance of high temperature corrosion resistant skeleton oil seal

Within the industrial sphere, high temperature corrosion resistant skeleton oil seals play a critical function, particularly in situations requiring extreme temperatures and corrosive conditions. These seals guarantee the dependability and safety of equipment operation in addition to shielding it from the deterioration of hostile environments. Ordinary sealing materials may deteriorate or fail in high temperature conditions, but corrosive media can swiftly damage sealing components, resulting in leaks and other associated issues. Thus, to preserve the integrity of industrial equipment and increase its service life, high temperature and corrosion-resistant skeleton oil seals are crucial.

1.2 The role of skeleton oil seals in industrial applications

An essential part of industrial machinery are skeleton oil seals. Their primary duties include sealing spinning shafts, stopping grease or lubricating oil leaks, and keeping outside impurities out of the machinery’s interior. Skeletons, elastomers, and sealing lips make up skeleton oil seals. Typically, the skeleton is composed of metal in order to provide the seal the support and form retention it needs. Skeletal oil seals are extensively utilized in a wide range of industrial machinery and equipment, including gearboxes, compressors, agitators, pumps, and so on. They are essential for preserving equipment functionality and cutting down on maintenance expenses. As industrial technology advances, skeleton oil seal performance has become more important.

2. Basic knowledge of skeleton oil seals

2.1 Definition of skeleton oil seals and their components

The component directly in touch with the rotating shaft is known as the sealing lip, and it is often composed of an elastic material that can adjust to the shaft’s movement to enable sealing.

Skeleton: A metal framework that supports and holds the sealing lip in place; occasionally, polytetrafluoroethylene (PTFE) or another material is also utilized.

Elastomer: Placed in between the sealing lip and the skeleton to maintain the seal’s overall elasticity and sealing ability.

A spring, which is occasionally added, gives the sealing lip more loading force so that it can stay in contact with the revolving shaft.

2.2 Working principle of skeleton oil seals

The principles of fluid dynamics and centrifugal force underpin the operation of skeleton oil seals. The centrifugal force produced by the shaft’s rotation will press the sealing lip against the shaft when it comes into contact with it, creating a sealing surface. Simultaneously, the oil seal’s internal structural design permits the lubricating oil to create an oil film on the shaft’s surface. Dynamic sealing is achieved by maintaining the sealing lip’s pressure on the shaft through the fluid dynamics created by this oil film during rotation.

2.3 Comparison between skeleton oil seals and traditional oil seals

Durability: Because they have skeletons, skeleton oil seals are often more resilient to long-term use than conventional oil seals without them.
Load capacity: Skeleton oil seals are appropriate for high-load application situations because they can sustain larger loads.
Installation and removal: Because of their construction, skeleton oil seals may be more difficult to install and remove than conventional oil seals.
Application: While typical oil seals may operate worse in high-temperature, high-pressure, and corrosive environments, skeleton oil seals are better suited for these circumstances.

3. Requirements for skeleton oil seals in high temperature environments

3.1 Effects of high temperature environments on sealing materials

The sealing materials used in skeleton oil seals are significantly impacted by high temperature settings. The softening and deterioration of sealing materials at high temperatures may result in a reduction in sealing performance. Certain rubber and plastic materials may soften or even melt when the temperature rises, making it hard to keep the seal in its initial form. High temperatures can also hasten the aging process of sealing materials, making them more brittle and more likely to fracture and shatter. Elevated temperatures may erode a material’s capacity to withstand chemical corrosion, leading to a reduction in chemical stability. Lastly, elevated temperatures may cause the sealing material to permanently lose its elasticity, which will hinder its capacity to rebound.

3.2 Stability and performance requirements of skeleton oil seals at high temperatures

Thermal stability: The substance must be able to withstand high temperatures without losing its chemical or physical characteristics.

Sustaining elasticity: The sealing material must continue to be sufficiently elastic to allow for the movement of the sealing lip and the rotation of the shaft even at high temperatures.

Mechanical strength: The material of the skeleton oil seal must be able to tolerate mechanical stresses at high temperatures since high temperatures can have an impact on a material’s mechanical strength.

Chemical resistance: The skeleton oil seal must have strong chemical resistance to avoid corrosion since it may be exposed to a range of substances at high temperatures.

3.3 The impact of high temperatures on the selection of skeleton materials and sealing materials

Skeletal oil seal material choice is directly impacted by high temperature conditions. It’s important to use materials for the skeleton that can endure high temperatures without losing their mechanical qualities, such stainless steel or certain alloys. These materials retain their structural integrity and load capacity in addition to their ability to tolerate high temperatures.

4. Importance of corrosion resistance

4.1 Discussion of the challenges of corrosive environments to skeleton oil seals

Skeletal oil seals have significant obstacles in corrosive conditions. Chemical media have the potential to erode the oil seal’s material, which would lower material performance and lessen the sealing effect. The sealing lip, skeleton, or elastomer of the skeleton oil seal may become cracked, bulge, or soften due to corrosion, which may ultimately result in seal failure and equipment damage. Furthermore, there is a chance that corrosive materials will seep into the environment via the oil seal, endangering public health and the environment.

4.2 Selection and application of corrosion-resistant materials

Fluororruber (FKM): It can withstand corrosion from a wide range of chemicals, has exceptional heat and chemical resistance, and works well in hot, corrosive conditions.
Polytetrafluoroethylene (PTFE): PTFE is a non-metallic skeleton material that is frequently employed in seals that come into contact with corrosive environments because of its exceptional resistance to chemical corrosion.

Silicone rubber: It is appropriate for situations requiring high temperature resistance and mildly corrosive conditions because it has good temperature resistance and resistance to certain chemicals.
Chloroprene rubber (CR): Applicable to some chemicals and outdoor conditions, it is recognized for its resistance to ozone and chemicals.

4.3 Applicability of skeleton oil seals in different chemical media

Acidic medium: Fluororruber and polytetrafluoroethylene are two examples of synthetic materials and specialty rubbers that can withstand erosion in acidic media.
Alkaline media: Chloroprene and silicone rubber are appropriate for alkaline conditions since they often exhibit good resistance to alkali.
Salt solution: Materials that can withstand salt erosion must be chosen for marine or saline regions.
Organic solvents: Some unique rubbers, including silicone rubber and fluororubber, may withstand the degradation of particular organic solvents.

5. Materials for high temperature corrosion resistant skeleton oil seals

5.1 Introduction to rubber materials suitable for high temperature and corrosive environments

Fluororruber (FKM) is a great material for high temperature oil seals because of its exceptional heat, oil, and chemical resistance. It can also tolerate severe temperatures and chemical degradation.
Silicone rubber is particularly well-suited for settings that demand resistance to oxidizing chemicals and high-temperature steam because to its strong heat resistance and some chemical resistance.
Acrylic rubber (ACM) is ideal for corrosive situations at mild temperatures because it has strong heat resistance, oil resistance, and resistance to certain acids and alkalis.
The benefits of silicone and fluororubber rubber are combined in fluorosilicone rubber, which also has improved resilience to high temperatures and certain chemicals.
Particular synthetic rubber: materials with high resistance to particular chemicals and conditions include chlorinated polyethylene (CPE), chlorosulfonated polyethylene (CSM), and so on.

5.2 Selection of skeleton materials: comparison between metal and non-metal

The metal skeleton is often composed of stainless steel or other unique alloys that possess strong mechanical properties and can withstand high temperatures and high pressures. However, in some chemical environments, metal skeletons could corrode.
Non-metal skeleton: materials with superior chemical resistance, including nylon, polytetrafluoroethylene (PTFE), and polyetheretherketone (PEEK), may not have the same mechanical qualities at high temperatures as metal skeletons. Non-metallic skeletons are frequently employed in corrosive settings, particularly in those where the presence of metals might result in chemical reactions.

5.3 The role of surface treatment technology in improving corrosion resistance

Coating: To avoid direct contact between the metal and the chemical medium, a chemically resistant coating, such PTFE coating, can be applied to the metal skeleton’s surface as an extra layer of protection.
Plating: The skeleton’s resistance to corrosion can be increased by chemically or electroplating a coating of a corrosion-resistant metal or alloy, such as zinc, nickel, chromium, etc., onto the metal surface.
Anodizing: Applying a thick oxide layer to some metal skeletons to improve their resistance to corrosion and wear.
Surface modification: Techniques like nitriding and carburization can alter the chemical makeup and surface structure of metals to increase their resistance to chemical corrosion.

6. Design optimization of skeleton oil seals

6.1 Design considerations for high-temperature corrosion-resistant skeleton oil seals

Material selection: Depending on the contact medium type and operation temperature, choose the proper rubber and skeleton materials.
Thermal expansion coefficient: To make sure the oil seal can continue to provide effective sealing across a range of temperatures, take into account the material’s properties related to thermal expansion at high temperatures.

Stress distribution: In order to prevent material fatigue or breakage brought on by stress concentration, optimize the design to guarantee that the oil seal’s stress distribution is consistent throughout operation.
Sealing lip shape: To avoid excessive wear or leakage, design a sealing lip that is appropriate for the shaft’s rotation speed and the medium pressure.
Design of heat dissipation: Take into account the oil seal’s heat dissipation needs and create a structure that effectively dissipates heat to avoid the oil seal failing from too much heat.

6.2 The impact of the design of the sealing lip shape on performance

Lip length: To produce a suitable sealing effect without generating excessive wear, the length of the lip form must be calculated based on the sealing medium’s pressure and the shaft’s rotation speed.
Lip angle: Depending on the particular requirements of the application, the sealing lip’s angle must be adjusted. This angle influences the sealing lip’s contact pressure and wear characteristics with the shaft.
Lip section: The sealing lip’s capacity to conform to the shaft and its sealing effect are determined by its cross-sectional shape, which can be Y-, V-, or U-shaped.
Material gradient: Its wear resistance and high temperature resistance can be increased by using composite materials in the sealing lip area that perform better.

6.3 Bonding technology of skeleton and rubber

Vulcanization bonding: This most popular bonding procedure creates a solid link between the rubber and metal skeleton by means of vulcanization.
Mechanical locking: In circumstances when vulcanization bonding is not an option, the rubber is fastened to the skeleton by means of a unique mechanical structure (such as rivets, snaps, etc.).
Chemical bonding: A particular glue is used to fuse the rubber and skeleton together. This technique works well with several unique material combinations.
Surface treatment: Roughening, plating, and other special surface treatments on the metal skeleton can strengthen the connection between the rubber and the skeleton.