7.9 Flashcards
(41 cards)
What are pipes and hoses dimensions determined by?
External diameter and wall thickness.
What pressures are high pressure lines?
Over 1500 psi (105 bar)
What pressure are medium pressure lines?
Under 1500 psi
What are low pressure lines?
Suction and return lines.
What are medium and low pressure lines preferably made of?
Aluminium for weight saving.
Where must steel lines be used?
Engine areas, areas in danger of fire and undercarriage where stones can hit.
What can titanium lines be used for?
Flexible metal pipes instead of hoses.
How are pipes and hoses proof tested?
With 1 1/2 it’s working pressure of compressed air and capping one end.
What are the 2 most common support clamps for pipes?
Rubber cushioned and plain.
What support clamps are used for pipes in areas subject to contamination?
Cushioned clamps utilising Teflon.
What is a bonded clamp used for on pipes?
Secure metal, fuel, oil or hydraulic lines.
What principle achieve the seal for flareless tube fittings?
Ball bush principle.
What are the 2 flareless fittings?
MS and Harrison.
How is a Harrison fitting secured?
Swaged in the sleeve from the inside.
What are the 2 types of flare?
Single and double flare.
What advantage do flared fittings have in engine areas?
They are vibration-resistant.
What is the standard flare angle?
37 degrees.
How are single flares formed?
Impact type or roll type.
What colour are flared AN fittings?
Black are blue.
What colour are AC flared fittings?
Grey or yellow.
What angle are AC flare fittings?
35 degrees.
Are AN fittings coarser or finer than AC fittings?
Coarser.
What size aluminium tubing can be double flared?
Outside diameter 3/8 in or smaller.
What is a disadvantage of a permaswage fitting?
It cannot be separated. Problematic on disassembly.
