People utilize hydraulic hoses to convey hydraulic power from pump to actuators, why are hydraulic hoses capable of these takes, they have two important features: they are flexible and can sustain working pressure from the hydraulic pressure in the inner hose. and then what are hydraulic hoses made of, in this article, we will dive into the construction and materials of hydraulic hoses.
Hydraulic systems are designed to transmit pressurized hydraulic fluid in a closed system, they include valves, actuators, pumps, reservoirs, and hydraulic hose assemblies, the former are fixed components in the system, however, the hose assemblies are mounted to link these elements in a flexible way.
The construction of the hydraulic hose
The hydraulic hose consists of three fundamental layers from the inner tube to the outer cover, and the middle layers are reinforced with textile and steel wire in some pattern, single or multiple, braided or spiral.
What are hydraulic hoses made of
When we talk about the materials that make hydraulic hoses, we have to indicate them separately in terms of their part and role. Rubbers are important polymer elastomers in the chemical industry, they are flexible in ambient temperature and have multiple resistance to corrosion, and rubber with certain recipes can be made to be used in the different parts of the hose.
The inner tube is exposed to hydraulic fluid and the material of the hydraulic hoses should be compatible with the hydraulic fluid coming in contact with it, the inner tube is generally made up of synthetic rubber like NBR (nitrile).
The outer cover is exposed to the ambient atmosphere, and they are susceptible to abrasion, ozone, and oil pollutants. The role of the outer cover is to protect the reinforcement and the tube from the outside environment. The rubber is generally SBR(styrene-butadiene rubber), Neoprene， and CPE rubber.
No matter the inner tube and the outer cover, they tend to be a mixture of several kinds of rubber, hybrid rubber aims to improve corrosion resistance and strength.
Except for synthetic rubber, and thermoplastic, Teflon is also used to fabricate hydraulic hoses. The thermoplastics used are often polyamide, polyester, and even fluoropolymers, which are highly resistant to solvents, and acids but have lower resistance to high temperatures. SAE 100R7 and R8 are examples.
Teflon has great features against high temperatures and strong chemical corrosion, SAE 100R14 is the instance.
The reinforcement layer entitles the hydraulic hoses with pressure resistance, fiber-braided hydraulic hoses are reinforced with nylon or polyimide wire, and steel wire braided or spiral hydraulic hoses are reinforced with steel wire, which is often plated with copper, the copper-plated wire can be more adhesive to the rubber and make them more like an integration when in the application.
Hydraulic hose materials often used
Nitrile Rubber (NBR)
To Create nitrile rubber, a polymer elastomer, the monomers butadiene, and acrylonitrile are copolymerized, Excellent oil, heat, wear, and solvent resistance levels are present.
As acrylonitrile content rises in the rubber, oil, heat, and abrasion resistance all improve. It has a long service life in hot oil at 120°C.
NBR is widely used in the inner layer of hydraulic hoses to transport hydraulic fluids because of its superior oil and heat resistance, making it suitable for most hydraulic oil media.
This rubber has a lesser cold resistance than other all-purpose rubbers, and its flexibility degrades over time, the resistance to cold decrease as acrylonitrile concentration increases.
Styrene and Butadiene Rubber (SBR)
With the monomers butadiene and styrene, SBR is a high-molecular-weight elastomer that has been copolymerized, SBR is compatible with other rubbers and is highly resistant to age, wear, and grease. SBR may be utilized as a utility hose to move water and air.
SBR cannot transport gasoline or petroleum-based liquids like natural rubber since it is not oil-resistant and would expand and become weaker.
To convey non-corrosive materials like air and water, SBR is frequently used to produce industrial rubber hoses, It is widely utilized as an auxiliary rubber in the hydraulic hoses’ outer construction.
Chlorinated Polyethylene Rubber (CPE)
The chlorine concentration substantially affects the performance of chlorinated polyethylene rubber because the chlorine atoms on the side chain give the bulk of the elasticity, With a rise in chlorine concentration, the elasticity progressively increases to become rubber, with a reduction in chlorine level, and the elasticity gradually declines to become plastic. A chlorine concentration of 25-35 should be present in the rubber.
The benefits of chlorinated polyethylene rubber include resistance to weather, ozone, heat, and chemicals, and excellent oil resistance. Chlorinated polypropylene is often used for hydraulic hoses’ outer layer.
Neoprene Rubber
Neoprene has excellent heat resistance, weather resistance, abrasion resistance, oil resistance, flame retardancy, etc., and is widely used in oil-resistant products, heat-resistant conveyor belts, acid and alkali-resistant hoses, sealing products, automotive aircraft parts, and cables Sheath, printing rubber roller, adhesive, etc.
Conclusion
Synthetic rubbers are the main component of hydraulic hoses because they have the flexibility and a variety of resistance, hybrid rubber mixture makes up for the drawbacks of single specific rubber, and makes hydraulic hoses strictly adhere to SAE and EN (European norm) standards.
Thermoplastics and Teflon hydraulic hoses make up for some special applications. Textile or steel wire reinforcement ensures their working pressure resistance.
When integrating rubber hose material and production technology in the workshop, batches of hydraulic hose are manufactured that adhere to the related criteria and the client’s requirement.
Sinopusle Group is a professional hydraulic rubber hose manufacturer, if you have some requirements about that, don’t hesitate to contact us.