General Information About the EO-2 Fitting
The large-volume elastomer ensures the hermetic sealing of the tube connection. It acts between the inner cone of the fitting body and the tube surface, thereby effectively blocking the only possible leak path. The special sealing profile has a particularly large cross-section to reliably seal even with unfavorable tolerances between the tube and the fitting.
The sealing effect is supported by the system pressure, making EO-2 fittings excellently suited for high-pressure applications. The high pre-tension of the seal ensures the outstanding gas-tightness of the fitting and thus prevents air from entering under vacuum conditions. EO-2 connections with permanently elastic sealing do not need to be retightened even under severe operating conditions. Typical seal damages such as gap extrusion or abrasion due to "pumping" are prevented by the optimized installation space without gaps or dead volume. The elastomeric seal is permanently bonded to the metallic support ring.
The retaining ring engages the tube wall according to the proven cutting ring principle. However, the dangers of over- and under-assembly are prevented: Before assembly, there is a gap between the end faces of the sealing ring and the retaining ring. This gap closes as soon as the retaining ring has reached the final cutting depth in the tube. The positive stop clearly signals the end of the assembly. This ensures a consistently good assembly result even with manual assembly. Complete assembly can be checked quickly and unambiguously by visual inspection of the gap.
Assembly to stop ensures effective protection against under- and over-assembly. This is achieved in the EO-2 fitting by the consistent separation of the sealing and retaining functions.
The metallic support ring of the seal acts as an integrated pre-assembly tool. Like a VOMO or MOK pre-assembly tool, this ring is characterized by its special geometry, material, and heat treatment. The integrated pre-assembly tool ensures that the retaining ring reliably cuts into the tube without damaging the fitting body. This unique feature even allows for the direct assembly of stainless steel tubes without an additional pre-assembly process. To reduce assembly time, effort, and costs, the proven EOMAT machines can of course continue to be used.
When using assembly devices, the integrated EO-2 assembly tool has a particularly positive effect: the pre-assembly tool of the device is only in contact with the elastomeric seal and therefore does not wear out. This not only saves the cost of replacing worn pre-assembly tools but also avoids leakage problems caused by assembly with worn tools.
The functional nut simplifies handling and contributes to reducing purchasing and storage costs. The sealing ring and retaining ring are non-removably joined in the functional nut, so these three parts form one construction element.
This means that individual parts such as seals or cutting rings cannot be forgotten, mixed up, or installed the wrong way around. During assembly, no individual parts have to be laboriously gathered.
The EO-2 functional nut fits all EO tube fittings. After assembly and disassembly, the sealing ring can be replaced individually without having to cut off the tube end.
High Corrosion Resistance
The Cr(VI)-free surface protection results in a corrosion resistance of an average of more than 500 hours against white rust.
Higher Nominal Pressures
EO-2 fittings can be used up to 800 bar (PN) in the S series and up to 500 bar (PN) in the L series. The requirements of DIN/ISO are clearly exceeded here. Due to the increased pressure ratings, the use of the L series is even conceivable where, due to design constraints, only the S series was previously considered. This not only reduces costs and assembly forces but also has advantages in confined installation spaces due to the smaller dimensions of the L series.
EO-LUB
The threads of the union nuts, which are coated with a sliding film as standard, are additionally treated with EO-LUB for dimensions from 25S/28L. This reduces the tightening forces of the EO-2 fittings by approximately 25 percent and helps to prevent dangerous under-assembly.
Cr(VI)-Free Surface Protection
By using a Cr(VI)-free surface protection, Parker Ermeto is responding to specifications from well-known automobile manufacturers who have banned the use of Cr(VI) since 2007. The "End of Life Vehicles" Directive of the European Parliament will exclude the use in the future or regulate the quantity used. The renunciation of Cr(VI) contributes significantly to active environmental and occupational safety.
Globally Available
EO-2 is available worldwide and complies with the standards for 24° cutting ring fittings.
High Sealing Capacity
The elastomeric seal acts as the primary sealing element. Even low-viscosity media such as water or gases are hermetically sealed. Therefore, hydraulic lines do not "sweat" at the connection points.
Excellent Long-Term Behavior
The soft-sealed EO-2 fitting does not need to be retightened even after years of continuous operation.
Defined Cut-In Depth
As soon as the gap between the sealing ring and the retaining ring is closed, the fitter receives a clear signal that the assembly is complete and the connection can be inspected. The ideal cut-in depth is therefore determined by the fitting design as well as by the fitter's force.
Functional Nut
Individual parts such as seals or retaining rings cannot be forgotten, mixed up, or installed the wrong way around during assembly. This helps to minimize assembly effort and avoid assembly errors.
Assembly Costs
With a cycle time of less than 10 seconds, pre-assembly with the EOMAT device is the most economical method. The actual pre-assembly process only takes about 1.4 seconds. The pre-assembly costs for the EO-2 connection are extremely low.
Integrated Assembly Tool
An integrated pre-assembly tool is located in every EO-2 functional nut. This ensures that the retaining ring reliably cuts into the tube without damaging the sealing surface of the fitting body. This effectively reduces the risk of tube pull-out, even when using stainless steel tubes.
Secure Reproducibility
When using EOMAT devices, there is no wear on the pre-assembly tools. This saves costs and effort for the regular inspection and replacement of worn pre-assembly tools. Assembly with heavily worn pre-assembly tools can lead to leaks in traditional cutting ring connections and, in extreme cases, to tube pull-out. EO-2 fittings are not as sensitive to the use of worn pre-assembly tools.
Clearly Noticeable Assembly Stop
As soon as the gap between the two rings is closed, the EO-2 connection is ready for assembly inspection and installation. Once the functional nut has been tightened wrench-tight afterwards, it is sufficient to tighten the connection with approximately 1/4 to 1/6 turn. The clearly noticeable fixed point increases the sense of safety and effectively prevents dangerous over-assembly.
Unambiguous Visual Inspection
Assembly inspection is simple and unambiguous: the assembly is complete when the gap between the sealing ring and the retaining ring is closed. The tube end can remain in the fitting during this process.
No Pseudo Leakage
No lubrication is required for the assembly of EO-2 steel fittings. There is no irritation from lubricant emerging from the fittings when the hydraulic system heats up.
Repeated Assembly
EO-2 fittings can be loosened and reassembled as often as desired. The sensitive sealing surface of the fitting does not wear out or widen. Damaged seals can be easily replaced. All replacement seals are clearly marked to prevent mix-ups.
On-Site Assembly
Standard wrenches are sufficient for on-site assembly and repair of pipelines. Changes to the piping or the installation of additional components such as measuring ports (GMA), ball valves (KH), or T-fittings can be done within minutes.
Interchangeability
EO-2 functional nuts can be used with all types, series, and dimensions of the broad EO fitting program. When switching from EO Progressive Ring or EO Weld Cone fittings, EO-2 functional nuts are simply used with the same fitting bodies.
Reliability
Millions of EO-2 fittings are used for applications such as: construction machinery, machine tools, hydraulic presses, plastic injection molding machines, shipbuilding, offshore exploration, submarines, railways, and military equipment. EO-2 fittings remain leak-free even after years of continuous operation.
Hassle-Free
With standard cutting ring fittings, typical assembly errors such as mixing up or installing cutting rings the wrong way around, or wear of pre-assembly tools often lead to failure. Due to the simple handling, these typical causes of failure are largely eliminated.
Popularity
Because of its superior performance and simple handling, the EO-2 fitting system is used as standard by renowned original equipment manufacturers. EO-2 fittings are specified by machine operators who do not want to forego leak-free performance, simple maintenance, and worldwide availability of metric cutting ring fittings.