Hydraulic hose is an important part of the hydraulic system. It is used in various machines that we use in our daily life. If you have no idea about it, we will help to understand this.
Today we will cover everything about hydraulic hoses. You will explore its manufacturing materials, types, uses and sizes in this article. Furthermore, after reading this guide, you can easily select and use the right hydraulic hose in your application.
What Are Hydraulic Hoses?
Hydraulic hose is a flexible and reinforced pipe that conveys hydraulic fluid to different components in the hydraulic system & transmit force. These components include pumps, valves, cylinders, or actuators. Hydraulic fluid mostly consists of oil such as mineral oil, water glycol, synthetic ester and biodegradable oil. When it passes through these components, it is used as an energy source to operate heavy machinery.
If we tell you further, it can withstand extreme pressures ranging from 35 PSI to 10000+ PSI. Additionally, it can handle severe temperatures up to -40℃ to 260℃. However, the exact pressure and temperature is based on the material, size and type of hydraulic hoses.
Hydraulic Hose Material and Layers
So, what are hydraulic hoses made of? Hydraulic hoses contain three layers, which are made up of different materials such as synthetic rubber, thermoplastic, PTFE and stainless steel. Now we discuss these layers, their materials and size, which is generally depends on the number of reinforcements:
Inner tube
First is the innermost layer that touches and carries the fluid. It contains synthetic rubber(nitrile), thermoplastic (polyurethane) and PTFE (polytetrafluoroethylene) material.
The thickness of the internal layer is around 0.04 to 0.12 inches (1.0mm to 3.0mm). One notable point is that the inner layer must match the type of fluid, so it resists harsh chemicals to prevent leak or degradation.
Reinforcement layer
Next is the reinforcement layer which makes the backbone of the hose. This layer is wrapped around the internal core to protect it. Its main job is to handle the maximum high pressure of fluid without deforming the shape of the hose.
It is composed of braided wire, spiral wound steel wire, helical or textile fiber. Each of them has its own capacity to tolerate pressure. The thickness of the strengthening layer is almost 0.012 to 0.12inches (0.3mm to 3.0mm).
Outer Cover
It is the last and outer layer which develops resistance to weather, abrasion, UV rays, ozone and chemicals. You can simply call it a protective layer because it protects the internal content from physical damage.
The most common material which forms outer covering is synthetic rubber, neoprene, PVC or thermoplastic rubber. Basically, the accurate material is based on the environmental requirement. If we talk about its thickness, it is around 0.04 to 0.10 inches (1.0mm to 2.5mm).
Hydraulic Hose Function
As we already told you, hydraulic hoses transport the pressurized fluid between different parts of machinery. It connects the reservoir tank, pump, valve and cylinder together in one working system. Now we come to its working or function.
- First of all, as the engine drives the pump, it takes fluid from the reservoir tank and pushes it to the system under high pressure.
- This pressurized fluid then enters into the hydraulic hose through the control valve.
- Next fluid passes through the inner core safely without leak and bursts under compression.
- The reason is the flexible nature and reinforcement of the hose that allows liquid to move smoothly even if the machine bends or shakes.
- Gradually fluid reaches the actuator such as cylinder or motor.
- As pressurized energy acts on the entire system, it pushes the piston and turns the motor to lift the heavy load.
List of Hydraulic Hose Types
This table will show you different types of hydraulic hoses and their features.
| Types | Composition | Temperature & Pressure | Properties | application |
| Braided hydraulic hose | Inner and outer layers made of synthetic rubber, with one to three braided steel wire or textile fibre reinforcement layers |
| High flexibility, average bend radius, good abrasion resistance | Automotive, agriculture, construction & manufacturing machinery |
| Multi-spiral hydraulic hose | Synthetic rubber inner tube and outer cover, four to six piles of parallel helical or spiral steel wire wound in alternating direction |
| High rigid strength, excellent shock absorber | Mining, forestry, construction & agriculture |
| Thermoplastic hydraulic hose | Polyester or polyamide internal layer, single steel wire or synthetic fiber braided strengthening film, polyurethane/ nylon outside cover |
| Lightweight, highly flexible, non conductive option available | factories , manufacturing and automotive |
| Low-pressure hydraulic hose | Nitrile or synthetic rubber interior core, textile or fibre braid supporting layer, rubber outer coating |
| Extremely flexible, easy to bend in tight spaces, Lightweight, kink resistant | Automotive, factories & agriculture |
| PTFE(Teflon) hydraulic hose | Polytetrafluoroethylene inner sheet, reinforced with stainless steel (outer cover depend upon hose design) |
| Universal chemical compatibility, non-stick interior | Automotive, manufacturing, chemical processing & aerospace |
Hydraulic Hose Standards
Hydraulic hose standards are official rules or guidelines that define the hose pressure ratings, material properties, testing methods and dimensions. Let’s suppose if you don’t follow these standards during the formation of hose. As a result, the hose made in one country will not handle the pressure or fit in the connector of the machine of another country.
SAE ( Society of Automotive Engineers)
The first one is SAE which is the most widely used specification. This standard is developed by the society of automotive engineers which cover the entire hydraulic hoses under J517 standard. It uses the 100R series (100R1 and 100R2) to classify the different hoses at their performance level which include hose design, dimension and strength.
The SAE standard allows the manufacturer to make the hose in such a way to meet the rules. It means after the formation it has to pass a test that is related to pressure, temperature and fluid compatibility. If we tell you further, this standard applies globally but holds a dominant position in North America.
EN (European Norms)
Next is European norms standard that derived from old German DIN standards. This international certification is mostly used in Europe. EN standards such as EN 853 and EN 857 confirms the quality and safety of hydraulic hoses. In addition, it determines the different types of hoses plus deal with dimension, performance and testing requirements.
ISO(International Organization of Standardization)
This standard is established for the worldwide system. ISO categorizes the hoses on the basis of pressure and performance. That is why you can use it anywhere like international infrastructure initiatives, global distribution networks and industrial equipment.
ISO and SAE relate with one another but differ in testing method and dimensional tolerance. ISO groups the hose how much pressure they can handle and SAE groups them how they are built.
Hydraulic Hose Uses and Applications
Construction and heavy machinery
It is commonly used in heavy construction machinery such as loaders, crane, excavator, dump truck, bulldozer and road roller. As fluid passes through hoses, it gives energy to the cylinder to do different tasks like lift heavy loads, dig earth and crush rocks. For this purpose, you can install spiral or braided hoses to bear harsh environment conditions.
Automotive & Transportation
They are also used in the hydraulic system of many automotives such as cars, buses and trucks. Its main job is to give power to the steering, brake, transmission and suspension system. This system helps in wheel turning, stops vehicles, transmitting energy and to adjust ride height. In short, we can say that it confirms the smooth functioning of the system.
Agriculture
As a farmer, you use tractors, loaders, harvesters and sprayers in your farms. You will observe hydraulic hose in the system of machinery. Fluids go through these hoses to move the equipment. As a result you can lift the dirt, cut the crops and sort them. To install in your farming equipment, you can choose thermoplastic or wire braided hoses.
Mining
If we talk about the mining field, it is the toughest environment for machinery. You will also notice these hoses in drills, excavators, crushers and transport material in this industry due to its durability. Hydraulic hoses used in that machinery have to face extreme conditions such as abrasive rock dust and bend in tight spaces. In this situation, you can use multi spiral hoses to tolerate such harsh environments.
Aerospace
You can see hydraulic hoses in aircraft such as airplanes, military jets and helicopters. It controls the reliable extension and retraction of wheels during landing and take off. Plus it also manages the flight control services, braking system and thrust reverser. Teflon hoses are mostly used in the aerospace industry.
Marine & Offshore
If you work in the marine and offshore industry, you can use hydraulic hoses in machinery for a variety of operations. It includes deck cranes, hatch covers, stabilizers, rudders and anchor winches. Stainless steel braided PTFE hoses can be ideal for use in salt water and high-humidity environments because they resist chemicals and rust to prevent degradation.
Manufacturing
You can see powerful machines in factories like hydraulic presses, injection molding, robotic arms and metal stampers. These machines use hydraulic hoses which carry fluid to power components for their movement and give shape to material. This industry needs flexible and durable hoses like hydraulic hoses to bear continuous heat and pressure cycles without burst.
Hydraulic Hose Size Chart
Below information will help you to find the correct inner diameter of hose.
| Dash size | Nominal hose ID (inches) | Nominal hose ID (mm) |
| -02 | 1/8″ | 3.2 mm |
| -03 | 3/16″ | 4.8 mm |
| -04 | 1/4″ | 6.4 mm |
| -05 | 5/16″ | 7.9 mm |
| -06 | 3/8″ | 9.5 mm |
| -08 | 1/2″ | 12.7 mm |
| -10 | 5/8″ | 15.9 mm |
| -12 | 3/4″ | 19.1 mm |
| -16 | 1″ | 25.4 mm |
| -20 | 1-1/4″ | 31.8 mm |
| -24 | 1-1/ 2″ | 38.1 mm |
| -32 | 2″ | 50.8 mm |
How To Identify Hydraulic Hose Size?
You can identify hydraulic hose size through measuring the internal diameter. Because the outer diameter varies by wall thickness and reinforcement layer.
- For this purpose, you can use the industry dash number which represents the inside diameter in sixteenth of an inch. For instance, -08 is 8/ 16 or 1/ 2 inch.
- You must check the printed text on the outer cover of the hose to find size, pressure rating and manufacturer.
- If it wears out with time and you cannot see it, you should use another method to measure it.
- In this situation, you should cut the unpressurized older hose safely from the center. Then measure the hole (bore) with a caliper or ruler to find the exact diameter.
- You can also measure thread size and type of attach fitting for this purpose.
How to Select correct Hydraulic Hose
If you want to replace the older hose and buy a new one but are confused how to choose the right hose. We recommend you to remember this STAMPED word before picking the hose. The reason is that each letter of its word represents one factor. Now we explain it one by one.
- Size: First of all, you must consider the size of hose such as its inner diameter, outer diameter and length. Because the accurate size is essential for flow rate and fit into the system path.
- Temperature: You should inspect its capacity to tolerate internal and external temperature ranges such as intense heat or cold. Otherwise, severe temperature can harden and degrade the rubber compound of the hose quickly.
- Application: Think about the environment where it is exposed such as ozone, UV rays, abrasion, bending cycle and harsh chemicals. Plus, you have to examine the specific location where it operates like indoor, outdoor, underground or water.
- Material: You must check the material of the basic three layers of hose. The inner core must be compatible with fluid (mineral oil & synthetic hydraulic oil) and the reinforcement layer withstand burden. But outer cover produces resistance to weather conditions and cuts.
- Pressure: Next we come to pressure rating. It means the hose must be strong enough to handle a high amount of pressure. You should pick the hose whose rated pressure is higher than the maximum working pressure of the system.
- Ends: Look at the couplings that you are going to put on the end of the hose to attach it to your equipment. You must match them based on material, thread type, sealing style and size.
- Delivery: Last one refers to flow rate which means how much fluid is passed through the hose. If you know this, it will help you to identify the hole size that must be used. The inside diameter of the hose must be adequate to keep pressure loss minimum, maintain liquid velocity and prevent excessive turbulence.
To Conclude
After learning everything about hydraulic hose, your main step is to choose the right manufacturer. But it can confuse you due to the number of suppliers in the market. RONTEIX is the most trusted company among them which make hydraulic hoses.
You can find all types and sizes of hydraulic hoses in our stock. Besides this, we also provide OEM/ ODM services for industrial and automotive hoses. For further information, you can contact us.
Frequently Asked Questions
What is the Average Lifespan of a Hydraulic Hose?
The average lifespan of a hydraulic hose ranges from 2 to 5 years under normal operating conditions. Though some can last up to 5 to 10 years based on the material type, number of reinforcement layers, use and maintenance.
Can You Replace a Metal Hydraulic Line With a Rubber Hose?
Yes, you can replace a metal hydraulic line with a rubber hose. This rubber hose must match the fluid type, pressure and temperature rating of the metal tube.
What are the Most Common Causes of Hydraulic Hose Failure?
The most common causes of hydraulic hose failure are external abrasion, fluid incompatibility, excessive bending, incorrect installation, aging, extreme heat and pressure.
Do Hydraulic Hoses Get Longer Under Pressure?
No, hydraulic hoses are no longer under pressure. In fact when a hydraulic hose is pressurized, it expands outward in diameter. This outward swelling pulls the internal wire braid tighter, which forces the hose contract and shortens the length.
