Figure 3-41.Correct and incorrect methods of installing flared fittings.
When tube-type fittings are being tightened,
observe the following:
Tighten only until snug. NEVER overtighten. More
damage has been done to tube fittings by overtightening
than from any other cause.
If a fitting starts to leak and appears loose, retighten
only until leak stops.
Where necessary, use two wrenches on fittings to
avoid twisting the lines.
Figure 3-42.Flareless-tube connector.
slightly at the midsection and acts as a spring. This action
of the sleeve or ferrule maintains a constant tension
between the body and the nut, thereby preventing the nut
FLEXIBLE HOSE CONNECTORS.Flexible
hose connectors are designed to be either permanent or
reusable and are made of forged steel. There are various
types of end fittings for both the piping connection side
and the hose connection side of hose fittings (fig. 3-43).
Before the installation of a new flareless-tube
connector, the end of the tubing must be square,
concentric, and free from burrs. For the connection to
be effective, the cutting edge of the sleeve or ferrule
must bite into the external surface of the tube.
Permanent hose fittings are discarded with the hose
when the hose is damaged or defective. They are either
crimped or swedged onto the hose. A crimping machine
that may be found in most shops does crimping of the
fitting. The crimping machine is either powered by hand.
an air pump, or a hydraulic pump.