A hydraulic hose is a high-pressure, thermoplastic, synthetic rubber, or Teflon reinforced hose. It is used to transfer energy-generating liquid between different components to form complete hydraulic machinery. In the early 1940s, engineers came across the hydraulic systems which were more compact, lighter in weight and viscous. Thus, this marks the beginning of the hydraulic machinery. There was a sudden increase in the development of hydraulic machinery during World War II for military applications. The development of flexible hydraulic hoses paved the way for the development of a wide range of new, high-powered machines rooted in hydraulic technology.
The basic fabrication of hydraulic hose consists of three layers which help in maintaining a consistent and reliable flow of liquid.
• Inner tube: The inner tube is designed to have the flexibility and needs to be compatible with the type of liquid it carries which allows both free-flowing elasticity and pressure-resistant stress bearing. Commonly used compounds in this tube are PDFE (PTFE), thermoplastic or synthetic rubbers.
• Reinforcement layer: This layer surrounds the inner tube and consists of one or more sheaths of coiled or braided wire. This arrangement helps in protection against the wear and tear while supporting the tubing.
• Outer layer: This layer is mapped by keeping in mind the environmental factors for which the hose is designed and to protect the entrails of the hose.
Selecting the proper hose:
There are number of factors which should be kept in mind while selecting the proper type of hose. In order to remember hose selection criteria, use the acronym- DAMPEST
• Delivery- While looking for hydraulic hose, it is advisable to consider different options to maximize flexibility and to avoid the delays that can result from the unavailability or short supply of different components.
• Application- Areas where the hose is being used.
• Materials- It is mandatory to check whether the tube is compatible to carry the fluid used in the system. The chemical compatibility of the tube and the fluid is influenced by the high temperature, fluid contamination, and its concentration.
• Pressure- Determine the system pressure and check if there is any external force or pressure acting on the hose.
• Ends or couplings –“Ends” refers to the endpoint of a hose required for connection or else known as “couplings.”
• Size: In order to select the proper hose size, it is important to measure the inside diameter, outside diameter and length.
• Temperature: Most hose materials have a working temperature ranging from 200° to 300° F based on the fluid temperature.
Types of Hydraulic Hoses
Depending upon the range of chemicals and pressures they will be pacified and due to its diverse applications, there are number of hydraulic hoses:
• Reinforced rubber: It is similar to the basic three-layer construction, but with additional buffers in the reinforcement layer, mostly in the form of a textile braid, wire braid, or wire helix material surrounding the inner tube. Bending, bulging or failure could be prevented with the use of stronger fibreglass or steel mesh in the Reinforced rubber hydraulic hoses.
• Coiled: They are designed in semi-rigid form for expansion and easy storage. To prevent unnecessary pressure on the hose, it is the coiled shape. Coiled hoses are used in many auto shops, welding shops and repair shops.
• Corrugated: Corrugation is used for increasing expansion and flexibility in a hose. It helps the hose in expanding and compressing without damaging the housing.
• Articulated: They are built in sections, with rigid shafts fastened by flexible joints. The articulation enables hoses to manoeuvre around corners or swivel around other components.
• The return lines: When the pressure is released, it brings fluids back to a pump. Proper maintenance and replacement are required to avoid a huge breakdown of the system.
A hydraulic hose is used anywhere in a hydraulic system which requires a flexible connection between two liquid ports. The flexibility and strength of the hose depending on the reinforcement windings that can be either braided or spiral wound.
The two primary purposes for which hydraulic hoses used are-
• To permit movement between two port locations.
• To decrease the effects of vibration.
A secondary purpose for which hydraulic hoses used are-
• To facilitate the installation or availability of hose manufacturing equipment.
• It is easy to use it up with ports that are not well aligned or have been modified because of its flexible nature.
Additionally, it can be used in large vehicles like aeroplanes which require hydraulics systems to operate wing movements and landing gear. They are also equipped on mobile equipment, cable carriers on injection moulding machines, automation, etc.
With the help of hydraulic hoses, a few ounces of pressure can result in hundreds of tons of output. Hydraulic machines can manage speed and movement of machines with extreme accuracy and create dynamic low-speed torque. Many different machines can be operated with a single hydraulic pump or compressor and that too at widely varying power levels at the same time.