Fluid Lines and Fittings Flashcards
The size of rigid tubing is determined by
Outside diameter
The outside diameter of rigid tubing is in increments of
1/16th of an inch
A -4 “B” nut has an outside diameter of:
4/16’’
A -10 “B” nut has an outside diameter of:
10/16’’
The two sizing considerations for rigid tubing are:
- Outside diameter
2. Wall thickness
Rigid tubing wall thickness is given in increments of:
thousandths of an inch
The method of finding the inside diameter of rigid tubing is to:
Subtracting twice the wall thickness from the outside diameter
When cutting a new piece of rigid tubing, you should ALWAYS cut it approximately ______ % (shorter or longer) than the tube being replaced.
10% longer
Why should the rigid tubing replacement be cut 10% longer than original?
To allow for margin of error for bending
What is the preferred method for rigid tube cutting?
circular tube cutter
To start cutting a rigid tube, mark the tube with
a felt tip maker
The finishing two steps in cutting a rigid tube with a circular tube cutter
- Deburr
2. Blow out with compressed air to remove chips
When bending lines for a repair, with complex curves and bends, you must produce bends that are ____% of
75% of the original tube diamter
What are the 3 types of rigid tube connections?
- Single/ Double flared connectors
- Flareless connectors
- Hose/clamps over a beaded tube
The type of fittings/ connectors used for fluid lines depends on 3 things:
- Pressure range
- Material being used
- Routing
A flared tube fitting consist of what 2 parts?
- B-nut
2. Sleeve
What is the advantage to using a B-nut and sleeve?
Protects the flare from damage as the nut is tightened
Two differences between AC and AN flared tube fittings
- AN fitting has a shoulder between the threads and cone, AC does not
- AN is longer for the same size
Color of AN flared tube fitting
Blue or Black
Color of AC flared tube fitting
Gray or yellow
Angle of the AC and AN flared tube fittings
35 degrees and 37 degrees respectively
Blue AN flared tube is made of:
Aluminium
Black AN flared tube fitting is made of:
Steel
The step necessary prior to installing a flareless fitting is called:
Presetting
What is presetting?
Applying enough pressure to the sleeve to cause it to cut into the outside of the tube
Before beading, what should you do to the part of the tube that is ready to be beaded?
Lubricate with oil
Fuel lines should be secured via
bonded line support clamps
Scratches or nicks in aluminium tubing are repairable as long as they are
no deeper than 10% of wall thickness and not in the heel of the bend
Dents in aluminium tubing are serviceable as long as they are
less than 20% of the tube diameter and not in the heel of the bend
Lines that carry fuel are labeled :
FLAM
Lines that carry generally dangerous fluids are labeled:
PHDAN
Why would you use a bullet or a slug for a rigid tube?
To repair a small dent
The 4 materials used for construction of the inner liner of flexible tubes:
- Buna-N
- Neoprene
- Butyl
- Teflon
Which material is most suitable for the use of Skydrol?
Butyl
What is important with in regards to servicing teflon hoses
Teflon “takes a set” and becomes rigid,
So DON”T bend it when you remove it
The laylines are typically which 3 colors?
- red
- white
- yellow
Medium pressure hoses are used for pressure up to:
3000 psi
The size of flexible lines is determined by:
inner diameter
The inner diameter of a flexible line is given in increments of:
1/16’’
Flexible lines must have between ____ and ____ slack to allow for
5-8% slack to allow for dimensional changes
The final step in a flexible hose fabrication is to:
clean the new hose assembly
