4300
Catalog
Assembly / Installation
Parker Hannifin Corporation
Tube Fittings Division
Columbus, Ohio
http://www.parker.com/tfd
S34
EO-2 Assembly
24
° Flareless Bite
PROBABLE CAUSE(S)
•
Improper ferrule/bite ring
orientation
•
Non-square tube cut; tube not
being properly supported in
seat of adapter
•
Tube not fully supported in
fitting’s body seat
•
Tube may be too hard; or
preset pressure or torque
might be too high
•
Tube is too thin
•
Improper preset or wrong tool
used for presetting
•
Worn preset tool
•
Too low preset pressure or
torque
•
Tube too hard
•
Tube not bottomed against
stop initially in preset
•
Improper preset
•
Tube too hard
•
Excessive internal pressure
•
Excessive axial load on tube
•
Inadequate make up
•
Overset ferrule
•
Cracked tube
•
Damaged components
RECOMMENDATION
•
Reset ferrule to ensure that the lead-
ing edge of ferrule/bite ring is pointing
towards end of tube and seat of the
mating fitting
•
Re-cut tube to 90° ± 1°
•
Reset tube end. This time ensure that
the tube is bottomed in the presetting
tool or fitting body
•
Use fully annealed tube max hardness
R B 72 for steel, R B 90 for stainless
steel
•
Consult manufacturer's minimum tube
wall thickness requirements; tube sup-
ports must be used with certain thin-
walled steel or stainless-steel tube.
Review preset requirements
•
In the presetting process, it is important
to exert axial force on the tube to keep
it fully bottomed in the tool. Check for
indentation on end of the tube
•
Replace preset tool
•
Observe manufacturer’s
recommendation for proper preset
•
Ensure that tube is of correct hardness
or material
•
Hold tube against stop in preset
•
Preset must be inspected for evidence
of proper preset, such as raised ridge
of metal in front of leading edge
•
Ensure that tube is of proper hardness
and material
•
Ensure that internal pressure is within
rating of fitting (tube might be of a
higher rating)
•
Avoid additional axial load than that
caused by internal pressure
•
Follow proper presetting and assembly
procedures
•
Excessive force used in presetting of
ferrule can cause it not to spring back
and effect a seal. Follow manufacturer’s
recommendation for preset
•
Check tube for circumferential crack
due to fatigue
•
Check components for damage such
as nicks, scratches and cracks
CONDITION
Immediate leakage when
system is pressurized
Additional/excessive stress
apparent on bite
Flexural stresses allow tube
to“rock” back and forth
Poor ferrule/bite ring pre-set
and/or tube collapse
Tube not bottoming out in
fitting body
Shallow bite of ferrule or cut
ring into tube
Tube pulls out of fitting in
application and ferrule skives
end of tube
Fitting nut is tight but leakage
still occurs