Hose Standards for Quality Hydraulic Hose
Hose Standards for Quality Hydraulic Hose
Hose Standards for Quality Hydraulic Hose
Hydraulic hose lines used in machinery and facilities are indispensable for many applications. However, increasing temperatures, operating pressures, compact and complex installation conditions and extended machine times lead to even greater stresses on the hose lines in the hydraulic system. Manufacturers of hydraulic hose lines are having to face these increasing demands.
In all applications and operating conditions of a system or machine, the safe and reliable operation of hydraulic hose lines is very important for operators. That is why hydraulic hose manufacturers are constantly working to improve the characteristics of their products and therefore their reliability and durability. A central component of this is the pressure-dependent development of the hydraulic hose. What has changed in the relevant standards in the last few years?
Tight Spaces require a smaller bending radius.
The installation situations of hydraulic hose lines are becoming more and more stringent, especially in mobile hydraulics. However, in order to ensure safe installation in line with the requirements, the demand for hydraulic hose lines with narrow bending radius is increasing. A comparison of two multi-spiral hose types with an inner diameter of 25 mm shows the latest developments in the field of compact hose types: High-pressure hose conforming to SAE 100 R15/ ISO at an operating pressure of 420 bar 3862 with four spiral inserts made of high-tensile steel wire the minimum bending radius is still 330 mm; In new generation hydraulic hoses, this is already much less than half. At the same working pressure, the compact hose with four spiral wire ends and maximum durability, conforming to ISO 18752-CC, has a minimum bending radius of only 150 mm; This is a huge advance.
Production Capacity Far Above the Standard
Similar major changes have occurred in hydraulic hoses for medium pressure ranges. Like all hydraulic hose lines, they must be pressure pulse tested in accordance with DIN EN ISO 6803. For manufacturers, this test is a prerequisite for hydraulic hose lines to be produced in accordance with the requirements and to obtain the relevant approvals. It also serves as proof of the functional safety of the components. Latest innovations show that these system test proof requirements have long been a common basic requirement and in many cases have already been surpassed by quality hydraulic hose lines. An example of this is the 2SN hydraulic hose to DIN EN 853 and its further development in the form of the 2SC compact hose type with two braided inserts made of high-tensile steel wire. Where standard 2SC must withstand at least 200,000 impact cycles in the pressure impact test in accordance with DIN EN 857, the new version sets a remarkable new benchmark. This type of hose has been impact tested with up to 1 million cycles, is characterized by a much smaller bending radius than the previous two models (2SN, 2SC) in all nominal widths, and the permissible working pressure also far exceeds the requirements of the standard.
Hydraulic Hose Fittings also need to improve.
Thanks to improved parameters, hydraulic hose lines can be used to solve challenging tasks of energy transmission in hydraulic systems increasingly safely and economically. However, the advantages of these numerous improvements only become truly apparent if the hose connections are also taken into account. This is because they are an integral part of the hydraulic hose line assembly and therefore crucial to its performance. It often happens that the hydraulic hose and fitting have different operating pressures. The lower operating pressure is decisive for marking and the maximum possible pressure load. This may mean that a dedicated hydraulic hose can be used for the desired application, but the hose coupling cannot be used; because the fitting is not designed for increased pressure load. As a result, a different type that meets the necessary conditions must be used.
Innovations in Hydraulic Line technology
Machine and system operators benefit from numerous advances in hydraulic line technology in a variety of ways: cost reductions, more compact installation and uniform product quality are just some of the added value. This is supplemented by higher safety functions, such as minimizing the risk of mixing up hose fittings at the connection points, which in some cases results from the mating of the threads of the light and heavy series.
Hydraulic Equipment Combination is very important
An example shows the role different operating pressures play in component selection: A hose coupling from the light series with 24° sealing cone and O-ring (DKOL15) is approved for a maximum operating pressure of 275 bar according to DIN 20066. If this connection is now combined with the high-performance 2SC compact hose with a maximum working pressure of 350 bar, the finished hydraulic hose line assembly can still only be operated at a maximum of 275 bar. Because here the weakest component is decisive.
Durability of hydraulic hose fittings under high pressure
For installation situations with higher operating pressures, heavy series (DKOS) hose fittings designed for operating pressures of up to 420 bar have been used until now. However, the use of heavy series may reduce the cross-section of the line depending on the connection size. In order to close this gap and find a solution to this conflict, manufacturers of light series hose fittings (DKOL and CEL) made of steel have achieved an increase in maximum working pressure in almost all nominal sizes through burst and impact testing. sherry. In this way, the combination possibilities for hydraulic hose line assemblies have been expanded many times.