Pipefitter Valves, Fittings, and Supports 5

Question 1

Which type of valve is best suited for applications requiring frequent operation and minimal pressure drop in the fully open position?

Accepted Answer

Gate valve

Answer

Gate valves have a straight-through flow path when fully open, resulting in minimal pressure drop, and are designed for fully open or fully closed service.

Question 2

A constant-effort (constant support) hanger is used when:

Accepted Answer

The pipe load must remain constant throughout vertical thermal movement

Answer

Constant-effort hangers maintain a constant load on the pipe regardless of vertical displacement caused by thermal expansion or contraction.

Question 3

What does the class rating (e.g., Class 150, Class 300) on a flanged valve indicate?

Accepted Answer

The pressure-temperature rating of the valve flange

Answer

Flange class ratings indicate allowable pressure-temperature combinations as defined by ASME B16.5, with higher class numbers permitting higher pressures.

Question 4

A 90-degree long-radius elbow has a centerline radius equal to:

Accepted Answer

1.5 times the nominal pipe diameter

Answer

Long-radius elbows have a centerline radius of 1.5 times the nominal pipe diameter (1.5D), which reduces turbulence and pressure drop compared to short-radius elbows.

Question 5

Which valve type uses a quarter-turn operation and provides a straight-through bore equal to the pipe diameter when fully open?

Accepted Answer

Full-port ball valve

Answer

Full-port (full-bore) ball valves have a ball with a bore matching the pipe ID, providing unrestricted flow with only a 90-degree turn to open or close.

Certified Pipefitter Practice Test

Certified Pipefitter Practice Test

Pipefitter Valves, Fittings, and Supports 5