PI 098-14 Lohr am Main, 2014-11-19

Lean mechanical engineering: 1 safety valve instead of 15

Compact and affordable: new LFA_DB_-7X/_E pressure relief values reduce material and installation costs.

Pressure relief cartridge valves by Rexroth simplify the design of hydraulic systems.

The new pilot-operated LFA_DB_-7X/_E 2/2 directional pressure relief cartridge valves by Rexroth ensure high flow and pressure at significantly lower cost than previous solutions. The safety valves type-examination tested under the Pressure Equipment Directive 97/23/EC simplify hydraulic circuits and reduce inspection effort during operation in addition to material and installation costs.

Cost pressure in mechanical engineering has been growing for years while machine safety requirements have become stricter. The new cartridge valves by Rexroth eliminate the need for previously necessary components in stationary hydraulic systems and contribute to reducing manufacturing and operating costs, as well as reducing the overall installation space needed in the block. With a relief pressure of 190 bar and a delivery volume of 3,500 l/min, this valve replaces up to 15 cartridge units. At 350 bar and 5,000 l/min, the ratio is 1:9. A size 63 cartridge valve can replace more than 10 existing single valves. This substantially reduces material and installation costs, as well as inspection effort. In addition to reduced material costs, the new valves significantly reduce installation time. Standard safety is certified through a type examination by TÜV Süd.

The porting pattern for the safety valves is in accordance with ISO 7368 (Form B) and also allows retrofitting in installed systems. The pressure limiter is integrated into the sealed control cover. The relief pressure is configured to the desired maximum value and sealed at the factory. In addition to a fixed maximum setting, Rexroth also offers a version that can be adjusted to lower pressure values at no additional charge. These can greatly simplify mandatory routine functional testing, which also reduces maintenance costs. The standard shaft seal of the main spool eliminates internal leakage. This means the new valves do not cause any power loss. At the same time, they enhance robustness against the “silting effect”, which can result in malfunctions primarily in short switching cycles due to screen filtration. Rexroth offers the LFA_DB_7X/_E safety valves in sizes 40, 50 and 63 with 4 graduated pressure ranges between 50 and 400 bar. They convey flows of up to 5,000 l/min.

Economical, precise, safe, and energy efficient: drive and control technology from Bosch Rexroth moves machines and systems of any size. The company bundles global application experience in the market segments of Mobile Applications, Machinery Applications and Engineering, Factory Automation, and Renewable Energies to develop innovative components as well as tailored system solutions and services. Bosch Rexroth offers its customers hydraulics, electric drives and controls, gear technology, and linear motion and assembly technology all from one source. With locations in over 80 countries, roughly 36,700 associates generated sales revenue of approximately 5.7 billion euros in 2013.

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The Bosch Group is a leading global supplier of technology and services. In 2013, its roughly 281,000 associates generated sales of 46.1 billion euros. (NB: Due to a change in accounting policies, the 2013 figures can only be compared to a limited extent with the 2012 figures). Its operations are divided into four business sectors: Mobility Solutions, Industrial Technology, Consumer Goods, and Energy and Building Technology. The Bosch Group comprises Robert Bosch GmbH and its roughly 360 subsidiaries and regional companies in some 50 countries. If its sales and service partners are included, then Bosch is represented in roughly 150 countries. This worldwide development, manufacturing, and sales network is the foundation for further growth. In 2013, the Bosch Group invested some 4.5 billion euros in research and development and applied for some 5,000 patents. This is an average of 20 patents per day. The Bosch Group’s products and services are designed to fascinate, and to improve the quality of life by providing solutions which are both innovative and beneficial. In this way, the company offers technology worldwide that is “Invented for life.”

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Susanne Herzlieb
Maria-Theresien-Straße 23
97816 Lohr am Main
Phone: +49 9352 18-1573

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