When it comes to hydraulic hoses, you may wonder why they can withstand high pressure when hydraulic fluids are pressurized and conveyed in the inner tube, that’s because of the reinforcement layer in the middle layer of the hydraulic hose. The hydraulic hose pressure rating is up to the structure of the reinforcement. A braided hydraulic hose is one of the typical reinforced patterns.
As the reinforcement layer is concerned, it tends to be textile or steel wire wrapped around the inner rubber hose with a braided/spiral woven pattern, this layer can offset the pressure composed in the inner wall of the hose and prevent the hose from exploring in high pressure. the style covers braided and spiral,
What are braided hydraulic hoses?
In the whole process of making hydraulic hoses, after extruding the inner hose, the following craft is to make reinforcement layers, and finally extrude the outer layer to wrap up the hose.
The braided hydraulic hose consists of an alternating crisscross pattern of steel wires or textiles to form a braid, the braid pattern overlaps each other over rubber or elastomeric hose and it takes place on the advanced braiding machine, the overlapped alternating angle is 54.44°, which makes the braided reinforcement withstand maximum pressure in a specific condition.
Advanced program control and considerate check assure the braid smooth arrangement, if one bunch of wire kinks over another, it not only affects the outer diameter of the final products, but also leads to a decrease of the pressure resistance.
The overlapping braiding results in the flexibility of braided hydraulic hose, and makes them with a lower bend radius, thus these can be mounted to the spots of limited room.
The type of braided hydraulic hose
Braided hydraulic hoses are divided into steel wire braided hoses and fiber braided hydraulic hoses in terms of materials adopted in the braided craft.
In terms of pressure resistance, braided hydraulic hoses often consist of a single braiding layer or two braiding layers, so we can have many pressure-rating hoses to opt for.
Steel wire braided hydraulic hose
Steel wire braided hydraulic hoses are the most commonly used hoses in the markets, as the name implies, The braided reinforcement originates from high-tensile steel wire, and the steel wires are copper-plated, it is researched that the adhesion between the copper and the rubber is higher than that between naked steel and rubber.
Single steel wires are joined into a bunch of steel wire on the joint machine, then put into braiding use.
The braiding process is fulfilled on the braiding machine, after extruding the rubber around the mandrel to form an inner tube, and the inner tube will be frozen at a lower temperature, and then be wrapped with one layer or two layers of braided steel wires. until now, we can see the steel wire reinforcement and inner rubber hose integrate together, the outer diameter will be checked and limited in the range of tolerance.
Steel wire braided hydraulic hoses are suitable for medium-pressure scenarios, or in a bit higger and lower range. their advantage is more flexible and easy to bend in a limited room. the most common examples are listed below:
Fiber braided hydraulic hose
Fiber braided hydraulic hoses are reinforced with textile, and they are manufactured with an advanced program-controlled braiding machine, they are more light and flexible than their metal wire-reinforced counterparts.
Fiber braid reinforced hydraulic hoses are lightweight and flexible for your medium and low-pressure hydraulic applications, with low-pressure hoses servicing operating pressures less than 300 psi, and medium-pressure hoses servicing up to 3,000 psi.
Braid vs spiral hydraulic hoses
Spiral wound hydraulic hoses are reinforced with bunches of steel wires and they are arranged in a parallel helical wound pattern. the commonly used hoses consist of four- or six-layer wounds in alternating directions.
Spiral hydraulic hoses can withstand high pressure but are less flexible and even very rigid, it brings some difficulty in some limited space.
Spiral hydraulic hoses are suitable for heat-duty and high-impulse applications such as hydrostatic drives, large off-road earth-moving dump trucks, or mining excavators.
Final words
Hydraulic hoses differ in material and variety of dimensions, they boil down to these two types of constructions: either braided hydraulic hoses or spiral hydraulic hoses, braided hydraulic hoses are reinforced with one or two layers of interlocking braid, more flexible with low- or medium usage, thus spiral hydraulic hoses are reinforced with parallel bunches of helical steel wires, more rigid in heavy-duty and high-impulse applications.
And then, the reinforcement layer(s) is the source of high-pressure resistance, when every batch of hydraulic hoses are completed, we always conduct pressure test to ensure they conform to the standard.
Sinopulse Group is a professional hydraulic hose manufacturer from China, we produce textile braided hydraulic hoses, steel wire hydraulic hoses, and spiral wound hydraulic hoses which comply with or exceed SAE and EN standards, if you are interested in these products or have some questions about that, don’t hesitate to contact us.