Parr Instrument 6200 User Manual
Page 14
15
6200
Calorimeter Operating Instruction Manual
Retightening
Swagelok
Tube Fittings
When Swagelok Tube Fittings are
used, the instructions for installation are:
1. Simply insert the tubing into the
Swagelok Tube Fitting. Make sure
that the tubing rests firmly on the
shoulder of the fitting and that the
nut is finger-tight.
2. Before tightening the Swagelok nut,
scribe the nut at the 6 o’clock
position.
3. While holding the fitting body
steady with a back-up wrench,
tighten the nut 1-1/4 turns. Watch
the scribe mark, make one
complete revolution and continue to
the 9 o’clock position.
4. For 3/16" and 4mm or smaller tube
fittings, tighten the Swagelok nut
3/4 turns from finger-tight.
Swagelok tubing connections can be
disconnected and retightened many times.
The same reliable leak-proof seal can be
obtained every time the connection is
remade using the simple two-step
procedure.
1. Insert the tubing with pre-swaged ferrules
into the fitting body until the front ferrule
seats.
2. Tighten the nut by hand. Rotate the nut to
the original position with a wrench. An
increase in resistance will be encountered
at the original position. Then tighten slightly
with a wrench. Smaller tube sizes (up to
3/16” or 4mm) take less tightening to reach
the original position than larger tube sizes.
The type of tubing and the wall
thickness also has an effect on the
amount of tightening required. Plastic
tubing requires a minimal amount of
additional tightening while heavy wall
metal tubing may require somewhat
more tightening. In general, the nut only needs
to be tightened about 1/8 turn beyond finger
tight where the ferrule seats in order to obtain a
tight seal.
Over tightening the nut should be avoided.
Over tightening the nut causes distortion
(flaring) of the lip of the tube fitting where the
ferrule seats. This in turn causes the threaded
portion of the body to deform. It becomes
difficult to tighten the nut by hand during a
subsequent re-tightening when the fitting body
becomes distorted in this manner.
2
2-3
Swagelok
Tube
Fittings