General Information About the EO-PSR Fitting
EO-PSR fittings create leak-free connections between pipelines and components in hydraulic systems. Due to its special geometry, the EO-PSR penetrates the tube in a defined manner, thus ensuring the sealing and holding function.
The progressive cutting of the ring is characterized by the fact that during assembly, the front cutting edge (A) has already begun to penetrate the tube before the second cutting edge (B) engages. When the functionally intended cut of both cutting edges is reached, further advancement is prevented by the stop contour (C) and the over-tightening protection (D). In addition, the special knurling at the start of the EO-PSR collar allows an assembly status check. Due to the geometry of the two cutting edges and the stop contour, applied forces are favorably transferred over the entire cone length. This distribution of forces and the specially designed inner contour at the end of the ring's collar (E) result in increased safety under bending fatigue stress. Vibrations are thereby already damped upon entering the ring.
The stop contour and the over-tightening protection cause a progressive increase in tightening forces during assembly up to a noticeable solid point (assembly fixed point). After completion of the assembly, the visible collar bulge (F) must fill the space in front of the first cutting edge. A slight rebound of the ring (G) is desired. This spring effect permanently compensates for bending vibrations and the setting behavior in the thread of the union nut.
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.
High Nominal Pressures
EO-PSR 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 high-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 particular 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-PSR fittings by approximately 25 percent and helps to prevent dangerous under-assembly.
Safe Assembly
Two distinct cutting edges ensure a progressive increase in torque for the EO-PSR. The stop contour creates a clearly noticeable assembly endpoint and significantly contributes to the highest assembly safety.
Over-Tightening Protection
The special geometry of the EO-PSR prevents over-tightening of the fittings.
Spring Effect
At the end of the assembly, an elastic preload is achieved (due to geometry, material, and heat treatment), which permanently positions the ring seat. Re-tightening of the EO-PSR fitting is not necessary due to the spring effect.
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 excludes or regulates the quantity used. The renunciation of Cr(VI) contributes significantly to active environmental and occupational safety.
Globally Available
EO-PSR is available worldwide and complies with the standards for 24° cutting ring fittings. The multifunctional EO-PSR ring can be used with all fittings and dimensions of the large Ermeto product range.