Page 134 - 4300 Catalog Cover.pdf

F10 Parker Hannifin Corporation
Tube Fittings Division
Columbus, Ohio
http://www.parker.com/tfd
EO and EO-2 Metric Bite Type Fittings
Catalog 4300
Fig. F5 —The unique Functional Nut allows easy handling and
quick assembly.
How EO-2 Fittings Work
The retaining ring bites into the tube in accordance to the proven
bite ring principle. The elastomeric seal reduces the danger
of over- or underassembly by a special EO-2 design feature:
Before assembly there is a gap in between the flat surfaces
of the retaining ring and the metallic support ring of the seal.
As soon as the retaining ring has reached the proper incision
depth, the gap closes, resulting in a sharp increase of assembly
torque. This results in uniform and reliable fitting assemblies.
The assembly result can easily be inspected by just checking
if the gap is closed.
The separation of sealing and holding functions to two separate
elements finally allows a more effective solution of the over-and
undertightening problems typically associated with bite type
fittings.
Assembly and Installation
Please refer to Section T for the assembly and installation in-
structions for EO and EO-2 Metric Bite type fittings.
Integrated Assembly Tool
The metallic support ring of the seal is made of a specially
designed material and heat-treatment to act as an assembly
tool. This makes sure that the retaining ring securely cuts into
the tube surface without damaging the sensitive inner cone of
the fitting body.
This unique feature of EO-2 fittings even allows direct assembly
of tubewithout any additional pre-assembly process.AnEOMAT
machine (or other hydraulic tool) is strongly recommended to
alloweasyassemblyof largedimension tubeanddrastically save
total assembly time, effort and costs. The integrated assembly
tool of EO-2 fittings even helps to save further costs and trouble
whenusinganEOMAT-typepresettingmachine:As thepresetting
cone is only in contact with the elastomeric sealing lip, it cannot
be worn out or damaged even after thousands of assemblies.
This not only saves replacement costs but also avoids leakage
problems caused by worn presetting tools.
The Functional Nut
The sealing and retaining rings are combined as a pair and
are inserted into the internal thread of the nut in such a man-
ner that they cannot fall out, so that these three parts form one
functional element.
Individual components such as seal or retaining ring cannot be
forgotten, confused or assembled in the wrong orientation.Time
and cost are saved by eliminating searching and arranging the
components to make up individual joints.
Functional Nuts are completely interchangeable with the full
range of EO tube fitting ends.
After assemblyanddisassembly, thesealing ringcanbe replaced
individually without cutting off the tube end.
Tube Recommendations
For steel fittings:
Seamless cold drawn steel tubes made from material St. 35.4
or from conditioned base material St. 37.4 in accordance with
DIN 1630, state of delivery NBK (normal annealed) with tube
outer and inner diameter tolerances in accordance with DIN
2391/ISO 3304. Max. hardness: HRB 75.
For stainless steel fittings:
Material no. 1.4571 and 1.4541
Seamless drawn tubes made from austenitic, stainless steel
materials no. 1.4571 and 1.4541, in accordance with DIN/EN/
ISO 1127. Max. hardness: HRB 90.
These tubes are particularly recommended for tube fittings,
since the tube outer diameter and wall thickness, tolerances
correspond to those of steel tubes in accordance with DIN
2391/ISO 3304.
Tube wall thicknesses:
In order to determine the necesary tube wall thicknesses for
applications, refer to the calculated pressures provided in the
tables for EOmetric tubing.The calculated pressuresDIN2413-I
are for static and DIN 2413-III for dynamic loads.
The maximum wall thickness is based on the pressure holding
capacity of the fitting. In some cases, the wall thickness of the
tube might be too thin for reliable service and an insert must be
used to prevent excessive tube collapse. See assembly section
for recommended tube wall thicknesses.
Plastic tube:
EO-2 fittings are suitable for use with various types of plastic
tubes such as nylon, polyethylene, etc. When used with plastic
tube, an insert (see page F15) must be used to prevent tube
pull out due to tensile loading.
The unique Functional Nut simplifies handling of fitting compo-
nents and helps to minimize storage and procurement costs.