Tanker Familiarization Tanker Systems and Equipment 4

Question 1

What does 'vapor pressure' of a cargo determine in tanker operations?

Accepted Answer

The volatility of the cargo and the required venting arrangements

Answer

Vapor pressure indicates how readily a liquid forms vapors; high vapor pressure cargoes require more robust venting and inert gas protection.

Question 2

On a gas tanker, what is the purpose of a reliquefaction plant?

Accepted Answer

To condense boil-off gas back into liquid cargo to minimize losses

Answer

A reliquefaction plant chills boil-off gas back into liquid, returning it to the cargo tanks and reducing cargo loss and vapor pressure buildup.

Question 3

Which safety device automatically stops a cargo pump if the discharge pressure drops dangerously low?

Accepted Answer

Low-pressure auto-stop (deadman) switch

Answer

A low-pressure auto-stop switch detects cavitation or loss of prime conditions and shuts the pump down to prevent mechanical damage.

Question 4

What is the purpose of 'tank gauging' using a closed (restricted) system on a chemical tanker?

Accepted Answer

To measure cargo quantity without opening the tank and releasing vapors

Answer

Closed gauging systems measure ullage electronically or by float, maintaining a sealed tank atmosphere and preventing release of toxic or flammable vapors.

Question 5

A tanker's 'high-level alarm' on a cargo tank is set to activate at what approximate fill level?

Accepted Answer

95–98% of tank capacity

Answer

High-level alarms typically trigger at 95–98% capacity to alert crew before the tank overflows, allowing time to stop loading.

Tanker Familiarization Practice Test

Tanker Familiarization Practice Test

Tanker Familiarization Tanker Systems and Equipment 4