Basics of Hydraulic Hose Assembly

Hydraulic fluid can be passed between the components by using tubes, pipes, and hoses. But, the hydraulic hose is one of the most important components in the hydraulic system that reduces the size of your system by offering flexibility and safety. Is it possible to design a hydraulic system by using only tubes/pipes? Yes, it is. But, that system will have many limitations. Because tubes and pipes are not so flexible if any system needs to be constructed, it will have more connectors and the size of the system will also get increased. Along with the increase in connectors, the chance for leakage will also get increase and the maintenance will become complicated. 

What is Hydraulic Hose Assembly?

         Tube, reinforcement, and cover are the major parts of every hydraulic hose. The inner tube will be closer to the fluid and the reinforcement & cover will act as a shield that protects the tube. This is about the structure of the hose. It is not easy to connect these hoses together or to join them with other components. When the user simply connects hoses, it can cause leakages. To prevent this, technicians/engineers use fittings that are normally constructed with metal. The fitting has a socket, that wraps the outer cover of the hose and a stem that enters inside the inner tube. 

        The procedure of effectively attaching fittings on both ends of the hose and then connecting it with the hydraulic system components for proper transmission of pressurized hydraulic fluid is called hydraulic hose assembly. For hydraulic hose assembly, the most important step is selecting a suitable hose and fitting required for the application. Now, let’s discuss the other factors that need to be considered for an effective hose assembly.

Hose size: Hydraulic hoses are available in different sizes from different manufacturers. It is the responsibility of the technician/engineer to analyze the hose requirements and select an appropriate one. Inner diameter is the key factor considered for hose selection. Hoses with a larger diameter and smaller diameter will affect the system's performance. That is if a hose with a larger diameter is selected, it will reduce the fluid pressure. Similarly, smaller diameter hoses will reduce the fluid flow. Both this information can be proved using Pascal’s law.

Temperature & Pressure: The operating environment of hydraulic systems will be different. It is necessary to consider the outer temperature and the inner temperature of the hose. Hydraulics used in automobiles will have high temperatures outside which can result in the damage of the hose cover and will gradually cause hose leakage. Not only this, if you consider any system that works continuously without an oil cooler, the inner temperature will be greater and cause wear in the inner tube. So, it is necessary to consider how much pressure a hose can withstand.

Fluid Compatibility: Hydraulic fluid selection depends on the system applications. Various properties of fluids are considered before selecting them. But, fluids have a key role in improving the lifespan of hoses. Most of the mineral oils are compatible with common hose varieties. But still, the user needs to consider fluid compatibility while selecting hoses and fittings.

Hydraulic Hose Assembly Replacement

          Once after assembling the hydraulic hose, it is necessary to maintain it properly. Both internal and external factors will affect the lifespan of the hose assembly. Contaminants, pressure, temperature, corrosion, etc…are the internal factors and external factors are those created by technicians by pulling, crushing, kinking, etc… 

       Hose assembly replacements can be done only with a proper visual inspection. Some symptoms of hose assembly failures are listed below.

• Hose Leakage
• Exposed wire(Abrasion)
• Cracked fittings
• Kinks in the hose
• Cracked or corroded fittings
• Twisted Hoses