Flexible Hose Fluid Lines

What are flexible hoses used for in aircraft?

Aircraft fluid systems

What do flexible hoses in aircraft fluid systems do? (3)

• Connect moving and stationary parts

• Accommodate vibration

• Provide flexibility where needed

What can flexible hose fluid lines serve as in metal tubing systems?

Connectors

What the five common hose materials

• Buna-N

• Neoprene

• Butyl

• EPDM

• Teflon

Which material is never used in the construction of flexible fluid lines?

Pure rubber

What is Buna-N resistant to?

Petroleum products

Which hydraulic fluid should you never use for Buna-N?

Skydrol

What is neoprene resistance to? (2)

• Abrasion

• Petroleum

Is Neoprene or Buna-N better for petroleum resistance.

Buna-N

Which hydraulic fluid should you never use for Neoprene?

Skydrol

What is Butyl made to be used with?

Skydrol

What should you never use Butyl with?

Petroleum

What is the innter tube structure of a hose made out of?

Seamless synthetic rubber

What is the inner tube structure of the hose covered with?

Layers of cotton braid and wire braid

What is the outer layer of a hose made out of?

Rubber-impregnated cotton braid

What are hoses normally classified by?

Amount of pressure they are designed to withstand

What are the three pressure classification?

• Low pressure

• Medium pressure

• High pressure

What PSI is low pressure?

<250 psi

What reinforcement does low pressure hoses use?

Fabric braid reinforcement

What is the PSI of medium pressure small sized hose?

3000 PSI

What is the PSI of medium pressure larger sized hose?

1500

How are medium pressure hoses reinforced?

One wire braid

What is the PSI of high pressure hoses?

Up to 3000 PSI