Per the basic hydraulics definition, a hydraulic hose handles liquid pressure and flow. When it comes to hydraulic design, hoses are NOT minor parts.
You must install the hose correctly. And, you should take care to select the correct type and grade of hose for its intended use.
Hydraulic hose comes in a myriad of design types and materials. Choosing the correct type for your application involves understanding several factors. Those factors include the hose’s intended application, use, environment, and so on.
This article contains everything you need to know about hydraulic hoses. We define hose types then go beyond that.
Read on for information on selecting the proper hose for your hydraulics application.
Hydraulic Hose Definition
A hydraulic hose conveys hydraulic fluid to or between hydraulic components. Components include valves, tools, and actuators. Hydraulic hose is usually flexible and reinforced.
Hose is often made up of several layers of reinforcement. This is necessary because hydraulic systems operate at high pressures.
Needless to say, hydraulic hoses are essential parts of any hydraulic system. The hoses are flexible enough to bend around corners and fit in tight spaces. They can also stretch over long distances.
What is Hydraulic Hose Made Of?
Hydraulic hoses are often constructed of multiple materials. The most common materials are fluoropolymers and silicone, elastomers, metal, and thermoplastics. Composite or laminated materials are also common.
Rubber and elastomeric hydraulic hose is a strong choice when you need flexibility. Fluoropolymer hose has a durable flex life as well. It also has excellent corrosion and chemical resistance, and it can handle high temperatures.
Thermoplastic hydraulic hose has a tight minimum bend radius. It also features superior resistance to kinks. Metal hoses handle high temperatures and high flow materials well.
They can also handle high pressures. Finally, they can be flexible or stiff.
Flexible hoses are easy to install and route compared to rigid tubing. The flexibility reduces noise and vibrations. It also dampens pressure surges and allows for movement between the parts.
Hydraulic Hose Construction
Most hydraulic hose consists of three main parts. They have an inner tube to carry the fluid. Next is a reinforcement layer, followed by a protective outer layer.
The inner tube is flexible and compatible with the fluid it will carry. A common compound is a combination of synthetic rubber, thermoplastics, and PTFE (Teflon).
The reinforcement layer has multiple sheaths. The sheaths include spiral-wound wire, braided wire, or textile yarn. The outer layer is often resistant to abrasion, oil, or weather, depending on its intended use.
Types of Hydraulic Hose
In addition to reinforced hose, hydraulic hose can be coiled, convoluted, or corrugated. Reinforced hoses come in several materials. Some of those materials include wire helix, textile braid, and wire braid.
Coiled hose is the choice for elasticity and flexibility. This makes coiled hose expandable as well as easy to store away.
Corrugated hose has pleats (corrugations) or spiral convolutions that increase flexibility. The result is a greater capacity for compression and elongation.
SAE and EN Standards
Manufacturers in the Americans, Australia, and Europe adhere to two sets of quality standards. One is the Society of Automotive Engineers (SAE) J517, and the other is the European Norm (EN) Standards.
SAE hose standards are the most popular benchmark in the hydraulics industry. To be more specific, J517 are guidelines that apply to the current SAE 100R series of hydraulic hoses. Sixteen hose styles exist.
SAE designates these as 100R1 through 100R16. Each style must meet a dimensional and performance characteristics, which SAE sets forth.
Meeting SAE standards is voluntary. Having these standards simply assured a similarity across products and different manufacturers.
EN standards evolved from on DIN German standards. Asian manufacturers follow these standards as well, but they gravitated toward EN specifications.
Much of this is because EN-rated hose has a higher pressure rating than the equivalent SAE hose. This provides better safety factors.
Selecting the Correct Hydraulic Hose
Even the most durable hose or hydraulic pipe has a finite life. To get the most life out of the hose, you’ll need to choose the correct size and type.
Missing the mark on this results in a marked reduction in the lifespan of the hose. According to SAE, here are some of the common errors in selection and use:
1. Flexing hose under the minimum bend radius
2. Twisting, kinking, pulling, or abrading the hose
3. Operating the hydraulic system below the minimum temperature or above the maximum
4. Exposing hose to pressure surges above the max recommended operating pressure
5. Mixing hose, assembly equipment, or fittings that are not compatible against manufacturer’s instructions
When selecting hydraulic hose for any industrial application, consider the needed dimensions and performance specifications.
The dimensions to consider for hydraulic hose are the inside and outside diameter. Also, consider minimum bend radius. The inside diameter, logically, is the inside of the hose or liner.
The outside diameter is a specification for corrugated or pleated hoses.
Minimum bend radius is a combination of two things. The first is the acceptable hose cross-section deformation. The second is the mechanical bending limit of the reinforcement.
When choosing a hydraulic pipe or hose, consider the type of fluid that’s conveyed. Also, consider the concentration of that fluid. Then consider any substances or chemicals in that fluid that may erode the hose cover.
The hose you choose must be resistant to any special oils or chemicals that may move through it. The same goes for the working environment in which the hose will work.
For example, ozone, UV light, chemicals, saltwater, and pollutants can degrade the hose. This can cause it to fail prematurely.
Consult with the manufacturer for compatibility specifications.
Which Hydraulic Hoes is Right for you?
You now have the rudimentary understanding needed to select the proper hydraulic hose for your needs. Remember that choosing the correct type and grade hose will extend its working life.
If you have more questions about hydraulic hose, please contact us.