Page 26 - Parker - Assembly/Installation

4300 Catalog Assembly / Installation
Ferulok Assembly

24° Flareless Bite

CONDITION PROBABLE CAUSE(S) RECOMMENDATION

Immediate leakage when • Improper ferrule/bite ring • Reset ferrule to ensure that the lead-
system is pressurized orientation ing edge of ferrule/bite ring is pointing
towards end of tube and seat of the
mating fitting

Additional/excessive stress • Non-square tube cut; tube not • Re-cut tube to 90° ± 1°
apparent on bite being properly supported in
seat of adapter

Flexural stresses allow tube • Tube not fully supported in • Reset tube end. This time ensure that
to“rock” back and forth fitting’s body seat the tube is bottomed in the presetting
tool or fitting body

Poor ferrule/bite ring pre-set • Tube may be too hard; or • Use fully annealed tube max hardness
and/or tube collapse preset pressure or torque R 72 for steel, R 90 for stainless
B
B
might be too high steel
• Consult manufacturer's minimum tube
• Tube is too thin wall thickness requirements; tube sup-
ports must be used with certain thin-
walled steel or stainless-steel tube.
Review preset requirements

Tube not bottoming out in • Improper preset or wrong tool • In the presetting process, it is important
fitting body used for presetting to exert axial force on the tube to keep
it fully bottomed in the tool. Check for
indentation on end of the tube

Shallow bite of ferrule or cut • Worn preset tool • Replace preset tool
ring into tube • Too low preset pressure or • Observe manufacturer’s
torque recommendation for proper preset
• Tube too hard • Ensure that tube is of correct hardness
or material
• Tube not bottomed against • Hold tube against stop in preset
stop initially in preset

Tube pulls out of fitting in • Improper preset • Preset must be inspected for evidence
application and ferrule skives of proper preset, such as raised ridge
end of tube of metal in front of leading edge
• Tube too hard • Ensure that tube is of proper hardness
and material
• Excessive internal pressure • Ensure that internal pressure is within
rating of fitting (tube might be of a
higher rating)
• Excessive axial load on tube • Avoid additional axial load than that
caused by internal pressure
• Inadequate make up • Follow proper presetting and assembly
procedures

Fitting nut is tight but leakage • Overset ferrule • Excessive force used in presetting of
still occurs ferrule can cause it not to spring back
and effect a seal. Follow manufacturer’s
recommendation for preset
• Cracked tube • Check tube for circumferential crack
due to fatigue
• Damaged components • Check components for damage such
as nicks, scratches and cracks

S26 Parker Hannifin Corporation
Tube Fittings Division
Columbus, Ohio
http://www.parker.com/tfd