Flareless fittings (figs. 6-44 and 6-45) are
suitable for use in hydraulic service and air
service systems at a maximum operating pressure
of 3000 psi and a maximum operating temperature
of 250°F. Flareless fittings are installed to
conserve space and to reduce weight, installation
time, and system cleaning time. Do not use
flareless fittings if you do not have enough space
to properly tighten the nuts or if you have to
remove the equipment or piping for access to the
Figure 6-45.--Typical flareless fitting.
fittings. An exception to this rule is a gauge board.
It is designed so it may be removed as a unit for
piping, fluid, and insulation. They absorb the
repairs or alterations. Do not use flareless fittings
movements imposed by thermal expansion of the
where you cannot easily deflect the piping to
pipe and the motion of the ship. The pipe hangers
permit assembly and disassembly.
and supports prevent excessive vibration of the
Before assembly, ensure the tubing end is
piping and resilient mounts or other materials.
square, concentric, and free of burrs. For an
They are used in the hanger arrangement to break
effective fitting, be sure the cutting edge of the
all metal-to-metal contact to lessen unwanted
sleeve or ferrule bites into the periphery of the
tube; you can do this by presetting the ferrule.
One type of pipe hanger you need to become
familiar with is the variable spring hanger. This
FLANGE SAFETY SHIELDS
is used to support the ship's bleed air piping. It
provides support by directly compressing a spring
A fuel fire in the MER or an AMR can be
or springs. The loads carried by the hangers are
caused by a leak at a fuel oil or lube oil pipe flange
equalized by adjustment of the hangers when they
connection. Even the smallest leak can spray fine
are hot. These hangers have load scales attached
droplets of oil on nearby hot surfaces. To reduce
to them with a traveling arm or pointer that moves
this possibility, FLANGE SAFETY SHIELDS are
in a slot alongside the scale. This shows the degree
provided around piping flanges of inflammable
of pipe movement from cold to hot. The cold and
liquid systems, especially in areas where the fire
hot positions are marked on the load scale. You
hazard is apparent. The spray shields are usually
should check the hangers when they are hot to
made of aluminized glass cloth and are simply
ensure that the pointers line up with the hot
wrapped and wired around the flange.
position on the load scales. You can adjust
hangers that are out of position by loosening the
jam nut on the hanger rod and turning the
adjusting bolt of the hanger.
Pipe hangers and supports are designed and
located to support the combined weight of the
INSPECTIONS AND MAINTENANCE
Reasonable care must be given to the various
piping assemblies as well as to the units connected
to the piping systems. Unless the piping system
is in good condition, the connected units of
machinery cannot operate efficiently and safely.
You should be familiar with all the recommended
maintenance procedures and observe the safety
precautions when working on piping systems.
The most important factor in maintaining
piping systems in satisfactory condition is keeping
joints, valves, and fittings tight. To ensure this
condition, you need to make frequent tests and
Figure 6-44.--Double-male flareless fitting.