Specifications and characteristics of hydraulic hoses are a vital consideration when selecting the right hose for your application. These include pressure ratings and abrasion resistance.
Return lines should be larger than pressure lines for safety reasons (see the manufacturer’s noograph). Also, bending the hose in more than one plane can reduce service life.
How hydraulic hoses can prolong service life
Hydraulic hoses are a vital component of any hydraulic system. They transport pressurized liquid to or from pumps and motors. These hoses need to be flexible to bend around equipment confinements, span long distances and resist high temperatures and operating pressures. They are usually made from multiple layers of materials such as elastomers and fluoropolymers.
The hose’s inner tube is usually constructed from a synthetic rubber such as nitrile (ACN) or a blend of butadiene and acrylonitrile. The material of the inner tube determines the hose’s compatibility with fluids and its resistance to abrasion, heat, oil degradation, low temperature flexing and chemical attack.
A reinforcement layer of braided wire or spiral-wound wire surrounds the inner tube to give the hose its strength and pressure-rated ability. The outer cover is usually made of rubber or thermoplastic, to protect the inner tube as well as provide environmental protection.
In order to get the maximum acceptable service life from a hydraulic hose, all components must be matched and assembled according to the manufacturer’s recommendations. This includes the couplings, which are either permanent or field-attachable and are categorized as screw-together or clamp-type. The coupling-to-hose mechanical interface must be compatible with the hose’s selected thread end to ensure leak-free connections.
The inner steel wire layer of a hydraulic hose can fracture for several reasons
The inner layer of an hydraulic hose is made up of a tube with a wire reinforcement. The tube material depends on the liquid it is carrying. For example, many manufacturers use polymers or thermoplastics that are compatible with petroleum-based fluids. It’s important to check a chemical compatibility chart before choosing the appropriate hose for a specific application.
Overpressure is a major cause of hose failure. Overpressure occurs when actual system pressure exceeds rated working pressure. This can result in a sudden rupture and damage to the hose assembly. It is recommended that a pressure limiter be used to control this problem.
Another common reason for hose failure is excessive bending. All bending affects the life of a hose to some degree, but twisting is more damaging than simple flexing. Twisting the hose causes larger gaps between the braided and wrapped steel wires. This reduces the hose’s capacity to withstand pressure.
Extreme temperatures can also reduce the lifespan of a hose. High temperatures can cause the rubber and plastic materials to melt or degrade. The hose can become rigid under pressure if it is not properly insulated. A good solution is to choose a higher-temperature hydraulic fluid, or a hose that is resistant to high temperature.
The main raw materials used to manufacture hydraulic hose
Modern hydraulic hoses are usually made up of three parts: a tube that transports the fluid, an outer cover and a reinforcement layer. Hydraulic hoses are made primarily of synthetic rubber, thermoplastics, and PTFE (also called Teflon). The material used in the reinforcement layer determines the pressure rating of the hose. It also depends on what fluids the hose is designed for. Neoprene, for example, is a polymer elastomer based on chlorine with excellent aging, flame resistance, oil, solvent, and air permeability. It has poor low temperature flexing.
The outer cover of the hydraulic hose should be weather and oil-resistant to protect it from abrasion and chemicals. It should also be able to withstand high temperatures. It is also advisable to use couplings that are permanently attached to the hose. These couplings are formed cold on the hoses using powered machinery. They offer a more reliable connection.
The construction industry is expected to grow, and this will increase the demand for hydraulic hoses. In addition, the demand for energy-efficient green buildings is anticipated to boost market growth. Hydraulic hoses are essential for the movement of these machines, as they provide a means of transporting fluids over long distances. They can be adapted to transport gaseous liquids, but the outer cover must be micro-perforated.
