Page 431 - 4300 Catalog Cover.pdf

4300 Catalog Assembly / Installation
Parker Hannifin Corporation
Tube Fittings Division
Columbus, Ohio
http://www.parker.com/tfd
T21
Underflared
assembly
Overflared
assembly
The flare must be reasonably square and concentric with the
tubeO.D.;and its surfacemust be smooth, freeof rust, scratches,
splits, weld beads, draw marks, embedded chips, burrs or dirt.
If the flare does not meet the above requirements, cut it off,
determine the probable cause from the troubleshooting guide
shown in Table T21,take corrective action and re-flare.
Fig. T29 – Underflaring and overflaring
Installation
Improper flaring or installation causes over half of the leakage
with flared fittings.Thus, proper installation is critical for a trouble
free operation.
Fig. T30 – Improper bend and short tube
Align the tube on the flare (nose) of the fitting body and tighten
the nut using one of two methods described below.
1. Flats from Wrench Resistance (FFWR) or “Flats” method
2. Torque method
Note: Do not force an improperly bent tube into align-
ment (Fig. T30) or draw-in too short a tube using the nut.
It puts undesirable strain on the joint leading, eventually,
to leakage.
Flats Method
Tighten the nut lightly with a wrench (approximately 30 in.lb.),
clamping the tube flare between the fitting nose and the sleeve.
This isconsidered theWrenchResistance (WR) position.Starting
from this position, tighten the nut further by the number of flats
from Table T20 .A flat is referred to as one side of the hexagonal
tube nut and equates to 1/6 of a turn.
This Flats method is more forgiving of the two. It circumvents
the effects of differences in plating, lubrication, surface finishes,
etc., that greatly influence the torque required to achieve proper
Condition Recommended Tightening Method
1. Plating of all comp- Either method is acceptable.
onents is the same. Use Table T20.
2. Plating is mixed. Use FFWR method.
3. Plating of nut and Use FFWR method.
sleeve or hose end
is unknown.
4. Parts are oily. Use FFWR method.
5. Stainless or brass Use FFWR method.
components.
Table T19 – Joint tightening method guide
Parker also recommends that wherever possible, the step of
marking the nut position relative to the body should be done.This
step serves as a quick quality assurance check for joint tighten-
ing. To do this, at the initial wrench resistance position, make a
longitudinal mark on one of the flats of the nut and continue it
on to the body hex with a permanent type ink marker as shown
in Fig.T31. Then, at the properly tightened position, mark the
body hex opposite the previous mark on the nut hex.
These marks serve two important functions:
1. The displaced marks serve as a quick quality assurance
check that the joint has been tightened.
2. The second mark on the body serves as a proper tighten-
ing position after a joint has been loosened.
The flats method is slower than the torque method, but it has the
two distinct advantages described earlier, namely, circumven-
tion of plating differences and a quick visual check for proper
joint tightening.
Torque Method
With proper tube flare alignment with the nose of the fitting,
tighten the nut to appropriate torque value in Table T20. T his
method is fast and accurate when preset torque wrenches are
used. Consistent component selection is recommended so that
the effects of dissimilar plating is not an adverse factor in joint
integrity. This makes it desirable for high production assembly
lines. However, a joint assembled using the torque method can
only be checked for proper tightening by torquing it again.
Note: This method should not be used if the type of plat-
ing on the fitting and mating parts (sleeve + nut or hose
swivel) is not known. The torque method should not be
used for lubricated or oily parts as improper clamping
forces may result. Over-tightening and fitting damage
may occur as a result.
Fig. T31 – Make reference mark on nut and tube body
Triple-Lok Assembly
joint tightness or clamping load. Therefore, it is recommended
to use this method wherever possible, and especially where the
plating combination of components is not known, and during
maintenance and repair where the componentsmay be oily.Use
Table T19 as a guide for proper tightening method.