Thursday, March 30, 2017 by
Hydraulic hose is more complicated than it seems. There are many factors that go into designing, manufacturing, and testing high-quality hydraulic hoses. At Parker Hannifin Hose Products Division, we take pride in our knowledge of the small details that go into hydraulic hose. This knowledge helps us produce high-quality hydraulic solutions for our customers.
Fast facts about hydraulic hose
- Hydraulic hoses and assemblies are frequently constructed of multiple materials, but the primary materials used are of the most importance. Rubber hydraulic hose is the most common but materials differ based on the requirements of the application.
- Elastomeric or rubber hydraulic hoses range from low to high pressure and are often selected for their excellent flexibility.
- Fluoropolymer hoses provide superior chemical and corrosion resistance and high temperature operation.
- Thermoplastic hydraulic hoses offer tight minimum bend radii and excellent kink resistance.
- Metal hoses can handle high temperature flow materials and often can handle very high pressures. They can be either stiff or flexible.
- Modern hydraulic hose typically consists of at least three parts: an inner tube that carries the fluid, a reinforcement layer, and a protective outer layer.
- The inner tube must have some flexibility and needs to be compatible with the type of fluid it will carry.
- The reinforcement layer consists of one or more sheaths of braided wire fabric or spiral-wound wire. The wire braid has a crisscross pattern around the perimeter of the hydraulic hose for flexibility. Instead of wires crossing each other, spiral wires remain parallel as they wrap around the hose.
- The outer layer is often weather-, oil-, or abrasion-resistant, depending upon the type of environment the hose is designed for. This layer is referred to most commonly as cover type.
- Hose vs Tube: Tube would typically be better when routed close to a heat source, and hose would be chosen for high vibration applications or when attached to moving parts. Hose is more flexible, available in longer lengths, quickly fabricated, easier to install in tight quarters, less vulnerable to corrosion and a better heat insulator.
- How long does a hydraulic hose last? So many variables come into play that it is impossible to exactly predict the service life of a hose assembly. Key factors to consider include size, temperature, application, media, and pressure. Parker created the STAMP process based on these five factors to help customers refine their hose search.
- Hydraulic hose size or inside diameter is sometimes referred to as the "Dash Size."
- Spiral hose is stronger than braided and can withstand higher pressures.
- Dirt and debris within a hydraulic fluid power system can cause tremendous damage very quickly. Oil contaminants can increase operating temperatures and damage components. Change the oil and filter regularly to prolong the life of your system.
- A hose assembly consists of a hose and hose fittings. Each of these components is rated independently in terms of working pressure. The maximum working pressure for the assembly is the lowest maximum working pressure between the fittings and hose.
Article contributed by Kyri McDonough, marketing services manager at Hose Products Division, Parker Hannifin.
Other related topics on hydraulic hose, hose application, and selection criteria:
Step-by-Step Hydraulic Hose Assembly
Top 8 Reasons Hydraulic Hoses Fail
Top 5 Reasons Customers Choose GlobalCore Hose
Successful Hydraulic Hose Assembly Starts Here
How to Choose the Right Fluid Power Hose
Going to Extremes: A Closer Look at Hydraulic Hoses