What is a hydraulic hose?
A hydraulic hose is a specialist hose used in industrial and commercial settings. Working in conjunction with hydraulic machinery, they connect valves, tools and actuators allowing fluids or gases to flow from one component to another.
Hydraulic hose assembly:
Hydraulic hoses comprise an inner tube within a reinforced layer and protective outer layers. The inner tube material is chosen to be compatible with the fluids, temperatures, pressures and impulses required of the hose. The outer layers are built up to suit the strength and durability required of the hose in its operating environment. A hydraulic hose’s composition must be robust enough to withstand both internal and external pressures.
The inner tube can be formed from synthetic rubber, P.T.F.E (commonly known as Teflon), or thermoplastics, depending on the properties and pressures of the fluids or gases within. The reinforcement can be made from single, multiple layers of braided wire, textile yarn or spiral-wound wire. The protective layer can be made of a range of resistant, repellent and flexible materials, depending on forces in the external environment.
What are hydraulic hoses used for?
Hydraulic hoses are essential in many industries, including waste management, manufacturing, agricultural and pharmaceutical businesses. They can be found on everything from vehicles and plant to specialist machinery or production lines, facilitating a range of processes including high pressure washing, gas lines, and spray paint applications.
Hydraulic hose safety:
As hydraulic hoses are used in essential industries or hazardous environments it is vital that proper product selection, hose assembly and maintenance is undertaken. This reduces the risk of physical, operational or environmental hazards or costly downtime.
What are the different types of hydraulic hose?
There are a wide variety of hydraulic hoses available, suitable for a range of pressures, impulses and temperatures during application.
Hoses can be differentiated by their external layers, to be selected for the durability against working pressures and external environment. These include:
- Braided hose – A versatile high pressure hose used in general industrial applications and suitable for almost all types of hydraulic applications with petroleum and water-based fluids.
- Spiral hose – A flexible high pressure hose suitable for use with high impulses and working pressures up to 50.0MPa, such as hammer hydraulics.
- Thermoplastic hose – A highly flexible hose with low volumetric expansion, giving excellent hydraulic response times and able to tolerate pressures up to 80.0MPa.
- P.T.F.E – A highly resistant hose, able to withstand a wide range of chemicals thanks to superior non-stick properties and being non-flammable, making it ideal for aggressive applications.
- Low-pressure hose – A textile braided hose, offering flexibility for lighter applications but unable to withstand high pressures.
- Stainless steel wire-braided hose – A heavy duty hose durable enough for aggressive applications and able to tolerate extreme external conditions.
There are also different types of inner tubes, including:
- Synthetic oil resistant rubber – Suitable for naturally occurring and synthetic fluids.
- Polyester – Suitable for both fluids and industrial gases.
- Polyamide – Highly resistant to fluids such as paints, chlorinated solvents and other chemicals.
- P.T.F.E – Highly resistant for use with chemicals and solvents.
What is MPa? A megapascal (MPa) is a metric to measure pressure. It is used to indicate pressure ranges and ratings for hydraulic systems, since it measures larger values – 1 megapascal = 1,000,000 pascals or 10 Bar.
Hydraulic hose standardisation:
Hydraulic hoses are governed by both industry and international standards – SAE Standards (set by Society of Automotive Engineers), and EN Standards – to ensure they comply with safety and performance standards.
How do I select the right hose?
Proper product selection and hose assembly is critical to the safe, efficient running of machinery and processes. The following factors of usage and application should be taken into consideration when selecting a hydraulic hose:
- Fluid/Gas types – Primarily, the fluids or gases which will flow through the hose, and the concentration of these, must be known and understood to determine the strength required of the inner tube. For example, aggressive solvents require highly resistant inner tubes.
- Temperature - Next the operating temperature of the fluids or gases must be known. This ensures high temperatures will not degrade the inner tube, or low temperatures will not impede its functionality as a conduit. Additionally, the external temperatures surrounding the hose must be known, ensuring the hose can function adequately within extreme temperatures or tolerate any temperature variations.
- Pressure – The pressures at which fluids or gases will flow through the hose will determine the strength required of all layers of the hose’s assembly, including the potential for pressure spikes. These operating conditions will dictate both the internal and external resistance required.
- Size – The size of your hose needs to account for adequate diameter and appropriate length. Internal diameter will be dictated by internal pressures while external diameter is dictated by the level of protection required or space available as well as the bend radius required. Overall length will depend on the distance between components and the flexibility required of the hose during use.
- Ends & Couplings – Thorough hose selection includes correct hose assembly to ends and couplings, ensuring durability and flexibility. The correct mating thread for ends will prevent leaks when sealed. These are essential in reducing the risk of potentially hazardous bursts or disconnections.
- Availability & Costing – The final hydraulic hose must suit your budget, operational capabilities and maintenance schedule to ensure efficiency and sustainability of the process. For example, if appropriate or necessary can elements of a hose’s application be adapted to accommodate a standard hose assembly that is more readily available or cost-effective.
Armed with all the above information, the right hydraulic hose can be chosen for your processes.
Why do hydraulic hoses fail?
Hoses can fail for many reasons, from incorrect installation to general wear-and-tear.
In busy work environments, hoses can become worn down through day-to-day use or be damaged through operator error. Products can also develop faults if they haven’t been correctly installed or maintained, such as insufficient routing or incorrect swaging risking a burst hydraulic hose.
The environment in which hoses are used can also have an impact. Externally, covers can deteriorate or become damaged due to the working environment, causing a hydraulic hose leak. Internally, tubes can degrade if there are spikes in the hydraulic system or incorrect pressures are used, or if fluids become contaminated or too hot.
Careful product selection and proper hydraulic hose assembly are essential – ensuring the best product is being applied and in the correct manner for the machinery or method in use.
How can you minimise the risk of hose failure and/or prevent a burst hydraulic hose?
Risks can develop through incorrect hose installation and usage, stresses in the hose environment, or user error.
Hose installation & usage
Understanding what’s required of a hose and the stresses it will be subject to is central to reducing the risk of faults or failure. Different products have different tolerances for temperature, fluid flow, flexibility and friction, both internally and externally.
Installing and assembling hose parts correctly is also key. Correct insertion depths must be met and hoses should be cut or swaged properly, without risk of inner tubes becoming contaminated or worn down.
The environment in which a hydraulic hose is used and the fluids or gases running through it will also impact its longevity. External forces and internal stresses can degrade or damage the hose, causing sudden ruptures or gradual wearing. Maintaining the environment surrounding a hose is important to reduce risk, preventing ruptures or abrasions. Inner tubes can crack, erode or even wash out if subjected to high velocities, contaminated fluids, or dry or aged air. Understanding the impact of internal fluids or gases and their temperatures or usage pressures will minimise risk.
How well a hydraulic hose is installed, used and maintained will hinge on the skill and understanding of operators. Ensuring workers recognise the importance of correct usage as well as the risks involved is key to minimising the likelihood of user error.
What are the risks?
Faulty hoses can cause operational, physical and environmental hazards.
Internal degradation can risk a hydraulic hose leak, where inner tube plastics wash into connecting machinery leading to costly repairs and downtime. A sudden burst hydraulic hose could cause serious injury to workers while a gradual leak risks creating a slip hazard. If hydraulic hose replacement or repair is not prioritised, potentially hazardous fluids could reach waterways, risking environmental harm, significant fines and reputational damage.
What are the benefits?
It's also important to recognise the many benefits of good hose installation and maintenance. Equipment which functions well improves overall productivity, delivers operational efficiencies and ensures worker safety. Investing in the right equipment and regular maintenance will pay dividends over time.
What to do when a hose bursts/fails (hydraulic hose repair):
Should a hose fail – whether through a leak, burst, breakage or disconnection – a partial repair or full hydraulic hose replacement may be required.
Broken or brittle inner tubes or coverings
Using a hose with greater resistance will prevent a hydraulic hose leak, as would applying a heat exchanger to manage fluid temperatures. Heat guards or shields can also protect hoses from external heat sources.
Worn or ripped covering
A worn covering suggests changes to the external environment will prevent further damage. Protective coverings can be applied or hose guards, shields or clamps can offer additional protection to connections.
Burst connection or covering
A burst hydraulic hose may be caused by a faulty connection or if it has been flexed too much in one spot by repeated high pressure cycles. Understanding what depth of fitting is required and how much flexibility or friction a hose can withstand will prevent bursts or disconnections.
Though there a number of factors that can cause a hydraulic hose to fail, many of the common causes are easily avoided through good product selection and proper maintenance. Investing in the right hoses and regular maintenance will reduce the risk of downtime to create long-term cost savings.
Our team can advise on the best products to optimize your processes, ensure good product durability and reduce the risk of failure.