English
Español
русскийThe choice of inner and outer layer materials of low-pressure oil hose directly determines its corrosion resistance during use, because oil hoses are usually exposed to various oils, chemical media, external environment and other factors, and are easily damaged by corrosive substances. Reasonable matching and selection of inner and outer layer materials can effectively improve the corrosion resistance of oil hoses and extend their service life. The following are several aspects of how the selection of inner and outer layer materials affects the corrosion resistance of low-pressure oil hoses:
1. Influence of inner layer materials
The inner layer material is directly in contact with fluids (such as oil, hydraulic oil, lubricating oil, etc.), so it is crucial to the corrosion resistance of oil hoses.
a. Polyurethane (PU) inner layer
Strong chemical corrosion resistance: The polyurethane inner layer has good chemical corrosion resistance, especially strong tolerance to many oils and solvents. It can effectively prevent oil corrosion and aging of the inner wall of the pipe, ensuring that the pipeline maintains its sealing during long-term use.
Oil resistance: The polyurethane inner layer has strong oil resistance to a variety of oils (such as diesel, lubricating oil, hydraulic oil, etc.), preventing oil from penetrating and destroying the inner layer structure.
b. Fluoroplastic (PTFE) inner layer
Best corrosion resistance: The PTFE inner layer material has extremely high corrosion resistance and can resist the erosion of almost all oils and chemical solvents. It is also very resistant to high temperatures, acids and alkalis, and is the preferred material for special environments.
Not easy to age: Fluoroplastic will not react with most chemicals, and will not degrade due to the chemical components in the oil, ensuring long-term stability.
c. Rubber inner layer (such as NBR, EPDM, etc.)
Oil resistance and chemical resistance: The inner layer of rubber materials usually uses nitrile rubber (NBR) or ethylene propylene rubber (EPDM), which can effectively resist the erosion of a variety of oils, hydraulic oils, fuel oils, etc. In particular, NBR materials have strong oil resistance and corrosion resistance, and are suitable for the transportation of conventional oils and general chemicals.
Temperature limit: Although the rubber inner layer can provide a certain degree of corrosion resistance, its high temperature resistance is relatively poor, so its corrosion resistance may be reduced when used in a high temperature environment.
d. Steel pipe inner lining
Metal lining: For some low-pressure oil pipes under high pressure or special environments, the inner lining metal (such as stainless steel lining) can enhance corrosion resistance and mechanical strength. The metal inner lining usually has better wear resistance and corrosion resistance, and is suitable for highly corrosive oil products and harsh environments.
2. Influence of outer layer materials
The outer layer material is usually used to protect the oil pipe from the external environment (such as ultraviolet rays, moisture, mechanical wear, etc.) and enhance the overall corrosion resistance of the oil pipe.
a. PVC (polyvinyl chloride) outer layer
Ultraviolet protection and anti-aging: The PVC outer layer can effectively prevent the damage of ultraviolet rays and prevent the pipeline from accelerating aging due to long-term exposure to sunlight. It also has good corrosion resistance and can prevent corrosion caused by moisture, salt, etc. in the external environment.
Mechanical protection: The PVC outer layer also has a certain degree of wear resistance, which can prevent external physical factors from damaging the pipeline in a more complex environment and extend its service life.
b. Polyurethane (PU) outer layer
High wear and corrosion resistance: The polyurethane outer layer can provide strong mechanical protection to prevent damage caused by friction, wear or collision. In addition, polyurethane has good resistance to corrosive chemicals such as acids, alkalis, and salts, and can effectively prevent external chemical media from corroding the oil pipe.
Low and high temperature resistance: Polyurethane materials have excellent high and low temperature resistance and are suitable for use at extreme temperatures, thereby enhancing the corrosion resistance of the oil pipe in harsh environments.
c. Rubber outer layer (such as NBR, EPDM, etc.)
Oil resistance and weather resistance: The outer rubber material (such as NBR, EPDM, etc.) has good oil resistance, wear resistance and weather resistance. Especially EPDM, which is suitable for use in areas with strong ultraviolet radiation or large climate changes.
Anti-aging: The rubber outer layer also has a certain degree of anti-aging ability, but it may age when exposed to sunlight and extreme environments for a long time, so it needs to be checked and replaced regularly.
d. Metal outer layer
Enhanced corrosion resistance: Sometimes the outside of the low-pressure oil pipe is coated with stainless steel or galvanized metal layer, especially for some applications that need to resist external highly corrosive environments (such as oceans, chemical plants, etc.) or high mechanical pressure. The solid protective layer provided by the metal outer layer can effectively prevent the surface of the pipeline from being damaged by external corrosive substances (such as salt water, chemical gases, etc.).
3. The influence of the combination of inner and outer layer materials
Multi-layer structure: Most low-pressure oil pipes adopt an inner and outer layer multi-layer structure, in which the inner layer mainly bears the corrosion and pressure of the oil, while the outer layer provides mechanical protection and environmental corrosion resistance. The coordination and selection of the inner and outer layer materials are crucial, and they need to be accurately matched according to the specific working environment and oil type. For example, the inner layer uses highly corrosion-resistant materials such as polyurethane and fluoroplastics, while the outer layer can use polyurethane, PVC or rubber and other materials with strong wear resistance and weather resistance.
Protection and enhancement: The functional coordination of the inner and outer layer materials can provide comprehensive protection in a variety of environments. The inner layer resists the erosion of the pipeline by oil products, while the outer layer enhances the protection against the external environment (such as mechanical damage, ultraviolet rays, moisture, salt, etc.).
4. The impact of different working environments on material selection
High temperature environment: In high temperature working environments, it is necessary to select inner and outer layer materials that are resistant to high temperature and aging, such as polyurethane, fluoroplastics or metal linings. These materials can maintain good corrosion resistance under high temperature conditions and are not easy to soften or lose elasticity.
Strong acid and alkali or chemical environment: For strong acid and alkali environments, it is necessary to use inner layer materials with good chemical resistance (such as PTFE or fluoroplastics), and select corresponding outer layer protection according to the environment, such as PVC or polyurethane.
Marine or salt spray environment: In marine or high salt spray environments, the salt corrosion resistance of the outer layer material is particularly important. PVC, polyurethane or metal outer layer materials are often used in such environments.
The choice of inner and outer layer materials of low-pressure oil pipes directly affects their corrosion resistance. The inner layer material mainly determines the corrosion resistance of the oil pipe when it comes into contact with oil or other chemical media, while the outer layer material focuses more on the resistance to the external environment (such as ultraviolet rays, moisture, chemicals, etc.). Reasonable material selection can effectively improve the corrosion resistance of the oil pipe and ensure its long-term stable operation in various environments. Therefore, the material selection of low-pressure oil pipes needs to be reasonably matched and optimized according to the use conditions (such as oil type, working temperature, environmental humidity, external corrosive substances, etc.).
