Rigid metal lines flexible hoses
Tubing sized according to wall thickness and outside diameter. OD is measured in 1/16th inch increments.
Stainless steel fittings
Nut fits over the sleeve and draws the sleeve and tubing flare tightly against the male fitting to form seal
The single flare and double flare
AN fittings have shoulder between the flare cone and the end of the thread, AC fittings do not
Sleeve length, thread pitch and shoulder between the threads and flare cone
The nut and the ferrule or sleeve
Flareless fittings don't have a flare cone and there is no space between the threads and the end of the fitting
The sealing surface may be damaged or the flare may cut off
The lines must be electrically bonded to the structure
It is compatible with nearly every liquid. broad operating temperature range, low resistance to fluid flow and has long shelf and service life
Lay line, identification markings, hose size, date code
The lay line will be straight if the hose is properly installed Twisted lay line if done incorrectly
Inside diameter, measured in 1/16th inch increments
The wall thickness must not be reduced in size or fractured.
Each half has a valve that is held open when coupled and is spring-loaded closed when disconnected
The tube is weakened when the nut drives the cutting edge of the sleeve too deeply into the tube
To provide a quick means to connect or disconnect a fluid line without loss of fluid or entrance of air into the system
1100-1/2 hard or 3003-1/2 hard aluminum alloy tubing
By its outside diameter.
To show the mechanic whether or not the line has been twisted when it was installed. The line should be straight, not spiraled.
The AN fitting has a shoulder between the end of the flare cone and the first thread. The threads of an AC fitting extend all the way to the flare cone.
Where the engine-driven pump connects to the hydraulic system.
By its inside diameter
The hose should be at least 5% longer than the distance between the fittings. This extra length provides the needed slack
Tighten the fitting by hand until it is snug, then turn it with a wrench for 1/6-turn to 1/3-turn. Never turn it more than 1/3-turn with a wrench.
5052-O and 6061-T aluminum alloy tubing in sizes from 1/8-inch to 3/8- inch OD