SPED Valve & Fitting Selection 2

Question 1

Which valve type provides the best throttling control for slurry services due to its straight-through flow path and full bore opening?

Accepted Answer

Pinch valve

Answer

Pinch valves use a flexible sleeve that is externally compressed, providing a straight-through, full bore flow path ideal for slurry and abrasive services.

Question 2

A piping system requires a fitting that changes pipe direction by 45° while minimizing pressure drop. Which fitting is most appropriate?

Accepted Answer

Long-radius 45° elbow

Answer

Long-radius 45° elbows have a centerline radius of 1.5× the pipe diameter, producing lower turbulence and pressure drop than short-radius alternatives.

Question 3

For cryogenic service at -200°F, which valve body material is preferred to prevent brittle fracture?

Accepted Answer

Austenitic stainless steel (ASTM A351 CF8M)

Answer

Austenitic stainless steels retain toughness at cryogenic temperatures because their FCC crystal structure does not undergo a ductile-to-brittle transition.

Question 4

Which end connection type is preferred for high-pressure, high-temperature service above 600°F where leak-free joints are critical?

Accepted Answer

Butt weld

Answer

Butt-welded connections eliminate threaded or socket crevices and are the most leak-resistant joint for severe service conditions.

Question 5

A check valve is required in a vertical pipe with upward flow. Which type is best suited for this orientation?

Accepted Answer

Lift check valve

Answer

Lift check valves are designed specifically for vertical pipe with upward flow, where gravity helps reseat the disc when flow stops.

(SPED) Society of Piping Engineers and Designers Certification Practice Test

(SPED) Society of Piping Engineers and Designers Certification Practice Test

SPED Valve & Fitting Selection 2