EVT EVT Hydraulic Systems & Aerial Apparatus 2

Question 1

When inspecting aerial apparatus outriggers, what must be verified before extending the aerial device?

Accepted Answer

Outriggers are fully deployed and pads on solid ground

Answer

Outriggers must be fully deployed and support pads placed on solid, level ground to provide the required stability before aerial operations.

Question 2

Which hydraulic fluid property is most critical for proper operation of aerial apparatus in cold climates?

Accepted Answer

Viscosity index

Answer

Viscosity index indicates how much a fluid's viscosity changes with temperature, which is critical for consistent performance in cold climates.

Question 3

What is the correct procedure when aerial apparatus hydraulic fluid appears milky or foamy?

Accepted Answer

Change fluid and inspect for water contamination source

Answer

Milky or foamy hydraulic fluid indicates water contamination, requiring immediate fluid replacement and identification of the water source.

Question 4

During an aerial ladder annual service test, how long must the aerial withstand the rated load test without retraction or lowering?

Accepted Answer

5 minutes

Answer

NFPA 1901 requires aerial devices to hold the rated load at the worst-case position for 5 minutes without measurable drift or lowering.

Question 5

What type of hydraulic fitting is preferred for aerial apparatus high-pressure lines due to its leak-free performance?

Accepted Answer

SAE O-ring face seal (ORFS)

Answer

SAE O-ring face seal (ORFS) fittings are preferred for high-pressure hydraulic lines because the O-ring provides a reliable, leak-free metal-to-metal seal.

EVT - Certified Emergency Vehicle Technician Practice Test

EVT - Certified Emergency Vehicle Technician Practice Test

EVT EVT Hydraulic Systems & Aerial Apparatus 2