The reliability of every component is significant for the design engineer of modern railway vehicles if they are to function smoothly in the long term.
The EO-2 fitting has been extremely reliable for application use in the rail industry. The soft-sealing fitting does not need to be re-tightened even after years of continual usage, and the seal is designed for long term cost savings.
Furthermore, it is always an advantage for the assembler when components are simple, safe and quick to install - easily carried out with commercial tools. But there are other benefits.
Advantages of EO-2
1. Ermeto design
The main advantage lies in the design detail. The EO-2 was developed on the foundation of the Ermeto Cutting Ring System - a well-known concept. It features a special characteristic - a large-volume elastomeric seal. Invisible from the outside, the seal assures sustained function and leak-tightness even in extreme application conditions.
The profile of the EO-2 elastomeric seal shows a particularly large cross-section which seals safely even in unfavourable tolerance ranges of tubing and fittings. So the sealing effect is supported by the system pressure. This means that EO-2 fittings are well suited for high-pressure applications. Due to the high preload of the seal, the EO-2 design has formidable gas leak-tightness. This prevents the penetration of air in vacuum conditions.
In comparison with other fitting types, the EO-2 Series has an advantage because of optimal installation room without gaps and dead volume. For the user typical sealing damage such as spiral extrusion or wear caused by “pumping” are prevented.
2. The “assembly to dead-stop” advantage
An ever-recurring problem is under- and over-assembly. EO-2 eliminates this because before assembly of the fitting, a gap is located between the end faces of the sealing and retaining ring. This gap closes as soon as the retaining ring has reached its final cut depth into the tube. Assembly completion by this dead-stop is very clearly indicated. An equally good assembly outcome is achieved with manual assembly too. So completed assembly can be checked by an operator's quick visual inspection.
3. Greater safety through clearly perceptible assembly stop
As soon as the gap between both rings is closed, the EO-2 connection is ready for assembly-inspection and installation. If the functional nut is then tightened to spanner tightness, it is sufficient to tighten the connection with 1/4 to 1/6 of a turn. This clearly noticeable stop point increases the user’s feeling of safety and prevents effectively dangerous under-assembly. And always remember this: “after fixed comes off”. This will certainly be avoided with EO-2.
4. Meeting the standards
EO-2 Fittings meet DIN 2353 and ISO 8434. They are available for tube sizes from 6 -42 mm O.D. – which covers most situations. For warm temperatures, it can be used with no problems up to +200 °C. Conversly, arctic temperatures pose no problems. EO-2 fittings are available in steel and stainless steel depending on your application.
All EO-2 fittings are certified in accordance with EN45545-2 and EN61363 and also have the IRIS certification. For the designer, this means a universally deployable fitting which meets the current certification standards. This significantly simplifies designs.
5. Wide application range and ease of assembly
A big application range means wider design possibilities. EO-2 covers hydraulic and pneumatic applications. For the user, there are clearly reduced costs and assembly work. In addition, this fittings series is also well suited to restricted access situations.
EO-2 are well-greased and easily assembled. The threads of the standard smooth-coated retaining nuts are additionally treated with EO-LUB from sizes 25S/28L. The torques of EO-2 fittings are thereby reduced by about 25 percent and make their contribution to preventing dangerous under-assemblies.
6. Save procurement and warehousing costs with the EO-2 functional nut
In the EO-2 functional nut the sealing and retaining rings are assembled so that these three parts cannot be lost and form one design element. Because of this, individual parts such as seals and cutting rings cannot be forgotten, mixed up or fitted the wrong way round. All these kinds of mistakes that might be made must be avoided at all costs because they affect the safety of both passengers and railway personnel.
Individual parts do not have to be laboriously collected together during assembly. The user can shorten assembly times, reduce warehousing costs and into the bargain increase the security of his/her systems free of charge.
Viewed on the whole, the EO-2 Series, represents an attractive, safe and reliable alternative to comparable fittings systems. EO-2 is available world-wide and in the case of replacement, makes the procurement of the required components easier. EO-2 also meets the “Buy America Act.” Click here to earn more about on EO-2 Fittings .
Article contributed to by Georg Kälble, manager marketing-service, High Pressure Connectors Europe, Parker Hannifin.