What is Hydraulic Hose? Material, Types, Usage & Standards

There are many types of hoses which you can buy from the market. All of them are used for their special purpose. Some include radiator hose, coolant hose, hydraulic hose and vacuum hose.

If we talk about hydraulic hose, it is mostly selected for transfer of fluid such as oil or fuel in the hydraulic system. If you need more information about the hydraulic hose, we have written necessary details in this article.

Hydraulic Hose Meaning

A hydraulic hose is a flexible and reinforced tube used to carry the hydraulic fluid between different parts of machinery such as pumps, valves, cylinders, actuators or motors. This fluid mostly contains the oil which is transported to these components to create the mechanical movement in heavy vehicles.

These hoses are used within the hydraulic system and can handle the extreme pressure range from 300 PSI up to 10000 PSI. In addition, it can handle the maximum pressure from -40℃ to 260℃ which is based on the type of hydraulic hose.

Hydraulic Hose Material: What is Hydraulic Hose Made of

Hydraulic hoses consist of three layers which are made up of material such as rubber, stainless steel, thermoplastic, teflon or fluoropolymer.

Inner Layer

The Internal layer of hydraulic hose is composed of synthetic rubber (nitrile or neoprene), thermoplastic (nylon or polyurethane) and teflon (PTFE). It touches fluid which means it can transport liquid. The thickness of the inner layer is almost 0.8mm to 1.5mm (0.030 to 0.0060 inches). The inner sheet must be compatible with fluid so that it cannot swell or corrode the innermost part of the hydraulic hose.

Reinforcement Layer

Next is the reinforcement layer which makes the hose strong and durable. It is formed from braided wire, spiral wound steel wire, stainless steel or textile fiber. Its role is to protect the inner layer and also helps in withstand the severe heat and pressure. If we talk about its thickness, it has a range 0.5mm to several millimeters.

Outer Layer

It is the upper portion which can bear the harsh weather conditions. You can call it a covering layer because it covers the reinforcement layers from abrasion, ozone, chemicals and cuts. It is also composed of neoprene, nylon and polyurethane. Outer layer thickness is almost 0.8mm to 2.5mm (0.03 to 0.10 inches) that is based on the overall hose size and structural standards. 

Hydraulic Hose Function

• The main function of a hydraulic hose is to transfer the fluid from one part to another part of equipment. 

• They join the components such as reservoir tank, pumps, valves, actuators or cylinders together in one working system.

• First of all, pumps push fluid from the reservoir tank into the valve, then it goes through the valve and reaches into cylinders. It performs its work and goes back to repeat the cycle.

• This fluid transfers power and force which make the machine move for their operation such as lift, steering, brake, dig, clamp, push and pull.

• Moreover, it maintains the pressure and flow rate according to the need of working.

• These are flexible and can be easily bent without break. Plus, it can also absorb vibration and bumps to prevent the hydraulic system from damage.

• In addition they have the adaptability to operate normally under very bad environments based on the material type. These conditions may include excessive temperature, pressure, corrosion, ozone and UV rays.

Types of Hydraulic Hoses

There are different types of hoses which you can use in your vehicle hydraulic system.

1. Braided Hydraulic Hose

Braided hydraulic hoses are available in various size and pressure limits which range from low to high. It also has three layers in which the internal layer and outer layer contains a synthetic or natural rubber. Whereas the supporting layer consists of one or more crisscross woven metal or textile braids. You can use this hose for oil or water based fluid.

Temperature: -40℃ to 100℃ (up to 125+)

Pressure: 300 to 5000 PSI

Wall thickness: 0.05 to 0.20 inches

2. Multi Spiral Hydraulic Hose

It is a strong and high weight bearing hose. They are made up of synthetic rubber and multiple strengthening layers of spiral steel wire. These spiral steel wires are parallel to each other which are wrapped around the hose and can tolerate the pressure more than braided hose. You can use them for transferring minerals, hydraulic oil, emulsion of water and oil in heavy machinery.

Temperature: -40℃ to 121℃

Pressure: 3000 to 6000 PSI

Wall thickness: 0.05 to 0.15 inches

3. Thermoplastic Hydraulic Hoses

These are bendable tubes and can easily fit into tight space without damage. The inner layer comprises nylon or polyamide and the outer cover consists of polyurethane. However, the reinforcement layer contains synthetic fiber (aramid or polyester) and steel wire. They are excellent resistant to chemicals and abrasion. You can use these hose mostly in forklift and utility bucket trucks.

Temperature: -40℃ to 100℃

Pressure: 1000 to 5000+PSI

Wall thickness: 0.015 to 0.060 inches

4. Low pressure Hydraulic Hose

This is a very flexible duct and is composed of synthetic rubber such as nitrile or neoprene. You can see it is reinforced with textile fiber and tolerates very low pressure. That’s why you can select them in lightweight applications for automotive oil, air, fuel and return lines. 

Temperature: -40℃ to 100℃

Pressure: 100 to 300 PSI

Wall thickness: 0.06 to 0.15 inches

5. Teflon (PTFE) Hydraulic Hose

Teflon hydraulic hose consists of PTFE inner core and reinforced with stainless steel braid. It does not need an outer layer but it may have more than one strengthening layer for protection of inner film. Because stainless steel provides resistance to rust and harsh chemicals which make it strong and durable. Furthermore, you can use it in heavy applications due to its ability to handle extreme temperatures.

Temperature: -54℃ to 260℃

Pressure: 600 to 5000PSI

Wall thickness: 0.02 to 0.12 inches

Hydraulic Hose Standards

The main international standards for hydraulic hose pressure are:

SAE: The Society of Automotive Engineers (SAE) established the standards for hydraulic hoses, fitting, assemblies, pressure rating and material quality. These standards define the suitability and performance between different manufacturers. They are commonly used in high pressure industrial fields such as construction, automotives, mining and aerospace hydraulic systems. These standards apply globally and in North America.

EN:  European Norms (EN) are widely used in Europe for quality and safety of hydraulic hoses. These are created to represent the size, tolerance, bending test and overall design. Basically, they are mostly used in mobile machinery, agricultural equipment and industrial units.

ISO: International Organization for Standardization (ISO) is implemented for global requirements. It classifies the hoses in such a way as to allow the maximum working pressure except strict construction rules. You can use it in international engineering projects, global manufacturing supply chains and heavy commercial machinery.

Following are the codes of these standards.

Hydraulic Hose Uses or Applications

Hydraulic hoses transfer the fluid under high pressure in the hydraulic system to move heavy parts, steer vehicles, and operate equipment efficiently in many fields.

Automotive

You can use hydraulic hoses in automobiles such as cars, trucks, buses and commercial transport vehicles. Wire braided and thermoplastic hoses are mostly used in automotives. You can apply these hoses in the power steering system for wheel turning and in fluid brakes system to stop the vehicle. Plus, the transmission system is used to transmit the power to different parts and suspension system to adjust the ride height.

Agriculture

These hoses provide the fluid power in tractors to raise the heavy farm tools and in harvesters to cut the crops and sort them. Whereas, loaders utilize them to lift the dirt or food. You can install wire braided and textile fabric hose in agriculture machinery especially in the steering control system and manure spreaders.

Construction

Hydraulic hoses can also be used in construction equipment such as excavators, dump trucks, loaders, concrete pumps, bulldozers, cranes, pavers and road rollers. Fluid is run in these hoses to give power for lift, dig, crushing rocks and other functions. For this purpose, you can install heavy duty multi spiral wire and abrasion resistant braided hoses in the system of these tools.

Mining

Mining equipment such as drills, crushers, excavators, roof bolters and material conveyors uses highly durable braided wire and multi spiral hoses. You can install these hoses because they have the ability to withstand shocks, constant vibrations, heavy load and provide support. These hoses transmit high pressure fluid to give power for their operation. 

Aerospace

You can also apply hydraulic hoses such as teflon hoses which contain stainless steel as an outer layer in aircraft for landing gear, flight control, braking system and cargo doors. It is capable of tolerating extreme temperature, stress and pressure. You can commonly install it in aerospace fields such as commercial airplanes, military jets and helicopters.

Marine

Stainless steel braided and marine grade PTFE hose which contain covers that are resistant to salt water make it ideal for marine applications. So, you can apply it in cargo ships, dockside cranes, anchor winches, offshore drilling machines. They use oil pressure which moves inside the tube to move the steering gears, lifting and hatch covers.

Factories

You can install standard rubber and thermoplastic hoses in industries for many purposes. Pressurized fluid passes through these hoses to give energy for operating the tools such as pumps, valves, motors or actuators. You can also apply it in assembly lines, robotics, hydraulic presses and injection molding machines.

Hydraulic Hose Size Chart

Inner Diameter: It is the internal size of the hose through which fluid passes. You can measure in 1 / 16 inch steps that are called dash size. If you want to replace an older hose with a new one, you should read the printed line on the outside of the hose. In case, you cannot see the size number because it wears out with time. You must cut the older hose in half and then measure the hole from inside with a ruler or caliper to buy the exact size. If you choose the wrong size, then it causes the pressure loss and affects flow rate.

Outer Diameter: Outer diameter is the entire thickness or width of pipe from one outer edge to another. It includes an inner core, hose wall and protective cover. You should check the hydraulic hose size chart to find the correct OD of hose to match the fitting of your vehicle. Because each hose has a different outer diameter, plus, it does not affect the flow rate.

Length: It is the total distance between two ends of hose which you can measure from one tip to other. You should measure the oil hose and add a little extra strength. So it does not pull tight when twisting. But long hoses can cause more friction and lose oil pressure. Furthermore, you must consider the length when calculating system pressure requirements.

Below is the table which represents the industry standard dimension for an SAE 100R2 high pressure hydraulic hose.

How To Choose the Right Hydraulic Hose?

To pick the right hydraulic hose, you must keep in mind the STAMPED method. In this technique, each letter represents each factor. Let's discuss them.

Size

First of all, you should check its dimensions such as inner diameter, outer diameter, length and wall thickness. As a result to maintain the flow rate and exactly fit into your vehicle path.

Temperature

You must check that the hose has the ability to withstand extreme temperature such as heat and cold. If it doesn’t have, then it will harden, soften, weaken and crack the hose. 

Application

You have to note where you want to use it, such as outdoors, indoors and underground. You must consider the environment conditions such as UV rays, abrasion, ozone and harsh chemicals under which these use.

Material

In addition, you should also match the fluid type (mineral oil, phosphate ester, water glycol and vegetable oil) which suits the inner core of the hose. Pick that hose which has an outer core to resist the weather, cuts and wear. 

Pressure

Look at those hoses who can tolerate maximum working pressure of your system. You should choose the hose with a pressure rating higher than your system’s peak pressure.

Ends

Before selecting, you have to identify the fitting and connection on both sides of the hose. Then you should match the thread type, size or sealing style like O ring or flared ends to your connection point.

Delivery

Lastly, you need to ask the seller, if they have your exact required length and right fitting like elbow or joints. Moreover, you should decide the number of pieces you want to order and the time limit for delivery.

FAQs

What is the Lifespan of a Hydraulic Hose?

The average lifespan of a hydraulic hose ranges from 1 to 5 years under normal working conditions. Whereas hoses reinforced with high quality steel can last up to 10 years. Actually, its accurate lifespan is based on the working usage, system pressure, operating temperature and maintenance.

Why Do Hydraulic Hoses Fail?

Hydraulic hoses fail mostly due to physical rubbing, extreme heat, fluid mismatching and wrong installation. These problems can weaken the inner tube or outer cover that causes the wear, crack, leaks and burst.

How To Identify Damaged Hydraulic Hoses?

To identify the damaged hydraulic hose, you need to see at outer visible cracking, soft spots, fluid leak and exposed wire braid. Furthermore, you can also observe kink or sharp twists and hard rubber. 

How To Maintain Hydraulic Hoses?

To maintain hydraulic hoses, inspect them every 3 months or 400 to 600 hours for abrasion, crack and leak. You should keep the fitting clean, avoid sharp bends or twistings and protect the line with abrasive sleeves.

Conclusion

Hopefully, after detailed discussion every thing about hydraulic hose will be clear to you. Their layers are made up of a variety of materials and are used in various industries. Now it depends upon your choice and your application.

If you want to buy hydraulic hoses and manufacture them according to your requirements. We are here to help you. Contact us and our engineers provide the exact dimensions & high quality products which meet all standards. 

See Also:

15 Types of Industrial Hoses: Features, Material and Uses

Silicone Vacuum Hoses – RONTEIX