CARO Piping Systems and Valves

Question 1

What is the primary purpose of a hand expansion valve (HEV) in an ammonia refrigeration system?

Accepted Answer

To manually control refrigerant flow into a vessel or evaporator

Answer

To automatically regulate refrigerant flow based on superheat

Answer

To relieve excess system pressure during emergencies

Answer

To separate liquid refrigerant from vapor in the suction line

Question 2

Which type of valve is most commonly used as a stop valve (shutoff valve) in ammonia refrigeration piping?

Accepted Answer

Gate valve

Answer

Ball valve

Answer

Globe valve

Answer

Butterfly valve

Question 3

What does a check valve do in a refrigeration piping system?

Accepted Answer

Prevents refrigerant from flowing backward in the piping

Answer

Regulates pressure by venting refrigerant to atmosphere

Answer

Controls superheat at the evaporator outlet

Answer

Balances pressure between high and low sides

Question 4

A pressure relief valve on a refrigeration vessel is required to discharge to:

Accepted Answer

A safe outdoor location or treatment system per code

Answer

The compressor suction line

Answer

The condenser inlet

Answer

The evaporator pan

Question 5

What is the function of a solenoid valve in a refrigeration system?

Accepted Answer

To electrically open or close refrigerant flow on demand

Answer

To manually throttle refrigerant flow

Answer

To continuously modulate refrigerant pressure

Answer

To separate oil from refrigerant vapor

Question 6

What material is most commonly used for ammonia refrigeration piping in industrial systems?

Accepted Answer

Carbon steel pipe

Answer

Copper tubing

Answer

PVC pipe

Answer

Aluminum tubing

Question 7

What is the purpose of a fusible plug installed on a refrigeration vessel?

Accepted Answer

To melt and release refrigerant if vessel temperature reaches a dangerous level

Answer

To prevent refrigerant from freezing in cold ambient conditions

Answer

To regulate liquid level inside the vessel

Answer

To isolate the vessel for maintenance