Guide to the types of hydraulic hoses: structure and features

Hydraulic hoses are essential components in hydraulic systems, designed to transmit pressure and power safely and efficiently. There are several types, which differ in material, structure and type of reinforcement, each suitable for specific operating conditions.

This guide examines the composition of hydraulic hoses and the main categories, focusing on the features of each layer and the most common classification criteria — providing a clear and technical overview to better understand how hydraulic hoses work.

Composition of a hydraulic hose

A flexible hydraulic hose is designed to withstand high pressure and ensure long-term reliability. It consists of three main elements: an inner tube, a reinforcement layer, and an outer cover.

Inner tube

The inner tube, also called the liner, is in direct contact with the pressurised fluid. It is generally made from polymer-based compounds and chemical additives, selected according to the type of fluid and operating conditions.

Common materials include:

• NBR (Nitrile Butadiene Rubber): excellent resistance to mineral oils, biodegradable oils and fuels.
• CR (Chloroprene Rubber): good resistance to mineral oils.
• PA (Polyamide): compatible with a wide range of fluids.
• PTFE (Polytetrafluoroethylene or Teflon): resistant to high temperatures and aggressive chemicals.
• EPDM (Ethylene Propylene Diene Rubber): suitable for phosphate ester-based fluids.
• AEM (Ethylene Acrylic Monomer): improved performance compared to NBR and CR.
• CSM (Chlorosulphonated Polyethylene): similar to CR but with higher heat resistance.

Reinforcement layer

The reinforcement is the structural core of the hose and determines its ability to withstand internal pressure. It can be made of different materials depending on the required performance and application:

• Metal reinforcements, made of braided or spiral-wound steel wires. Typically, 1, 2 or 3 wire braids are used for medium to high pressures, while 4 or 6 spirals are used for very high pressures and severe impulse conditions.
• Textile reinforcements, made of aramid fibres, provide greater flexibility and lower weight than metal reinforcements, though with lower working pressure.
• Polyester reinforcements, mainly used in thermoplastic hoses, offer a good balance between flexibility, strength and lightness, and allow the production of non-conductive hose versions.

A thin adhesive rubber layer, known as the bonding layer, is applied between the different layers to improve cohesion and form the hose carcass.

The reinforcement is what allows the hose to withstand internal pressure — the inner tube alone would not be able to resist it.

Outer cover

The outer cover protects the hose from external factors and completes its structure. It is designed to resist:

• abrasion,
• weathering and chemical agents
• ozone, heat and UV radiation

Different combinations of materials can be used to achieve the desired levels of flexibility, resistance and durability.

For particularly demanding applications, additional sleeves or protective sheaths can be added to further enhance the hose’s protection.

Types of hoses by reinforcement

Hydraulic hoses can be classified according to the type of internal reinforcement, which determines the maximum working pressure, flexibility, weight and typical applications. The main categories are:

• Braided hoses

In braided hoses, the reinforcement consists of one or more layers of interwoven steel wire.
They offer a good balance between pressure resistance and flexibility, making them suitable for applications such as agriculture, earthmoving, lifting and more.
They are typically used where pressures are not extreme but ease of handling and compact size are required.

• Spiral hoses

In spiral hoses, the reinforcement consists of multiple layers of steel wire wound in a spiral (usually 4 or 6).
This design allows the hose to withstand very high pressures and strong impulses, maintaining resistance to high temperatures and harsh environments.
They are ideal for heavy-duty applications such as drilling, mining and marine sectors.

• Textile hoses

In textile hoses, the reinforcement is made of non-metallic fibres.
These hoses are suitable for medium- to low-pressure applications, such as delivery or suction lines, where flexibility and lightness are key.
Although their working pressure is lower than metal-reinforced hoses, they offer good handling and versatility.

Types of hoses by cover

Hydraulic hoses are also distinguished by the type of outer cover, which protects the inner layers from external factors and determines the hose’s durability, abrasion resistance and weather performance.
The main cover types are:

• Synthetic rubber: Provides protection against abrasion, ozone and atmospheric agents.
  It can have a smooth or wrapped finish, depending on the vulcanisation process (extruded sleeve or fabric wrap), which leaves a characteristic surface texture. The advantages of a smooth cover include:

• • easier to clean
  • ideal for use with hose reels
  • easier to fit protective sleeves
  • lower friction and better abrasion resistance

Special high-resistance versions are also available, designed to significantly reduce wear from abrasion and improve durability in harsh conditions.
Some versions are MSHA-certified for mining and extreme environments, while others feature polyethylene coatings, offering outstanding resistance to abrasion and ozone.

• Polyurethane (PU): Commonly used in thermoplastic hoses, polyurethane combines lightness and flexibility with excellent abrasion and UV resistance. It is ideal for applications where hoses are exposed to abrasive surfaces or direct sunlight.

These cover types help identify the most suitable hose for specific working and environmental conditions.

Reference standards for hydraulic hoses

The technical standards governing hydraulic hose manufacturing define essential safety, performance, compatibility and interchangeability requirements.

Compliance with these standards ensures that each hose operates reliably under the specified pressure, temperature and flow conditions — reducing the risk of failure and extending system lifespan.

The main reference standards are:

• EN (European Norms) – used across Europe, specifying construction and performance requirements for the various hose types.
• SAE (Society of Automotive Engineers) – mainly applied in the United States, regulating materials, pressure tests, and testing methods.
• ISO (International Organization for Standardization) – representing international standards, aiming to integrate the requirements of other norms to ensure global compatibility.

Comparison table – EN, SAE and ISO Standards

Further Information

Understanding the structure and characteristics of hydraulic hoses is essential to grasp how they function and perform under different operating conditions — and to know how to choose the right hydraulic hose.

You can browse our product catalogue to explore the available hose types and their technical specifications.
For any questions or requests for additional information, you can contact us via the contact form to receive tailored support and advice.