Valve & Fitting Selection Flashcards
7 cards from real SPED practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Valve & Fitting Selection flashcards as text
Which valve type provides the best throttling control for slurry services due to its straight-through flow path and full bore opening?
Answer: Pinch valve
Pinch valves use a flexible sleeve that is externally compressed, providing a straight-through, full bore flow path ideal for slurry and abrasive services.
A piping system requires a fitting that changes pipe direction by 45° while minimizing pressure drop. Which fitting is most appropriate?
Answer: Long-radius 45° elbow
Long-radius 45° elbows have a centerline radius of 1.5× the pipe diameter, producing lower turbulence and pressure drop than short-radius alternatives.
For cryogenic service at -200°F, which valve body material is preferred to prevent brittle fracture?
Answer: Austenitic stainless steel (ASTM A351 CF8M)
Austenitic stainless steels retain toughness at cryogenic temperatures because their FCC crystal structure does not undergo a ductile-to-brittle transition.
Which end connection type is preferred for high-pressure, high-temperature service above 600°F where leak-free joints are critical?
Answer: Butt weld
Butt-welded connections eliminate threaded or socket crevices and are the most leak-resistant joint for severe service conditions.
A check valve is required in a vertical pipe with upward flow. Which type is best suited for this orientation?
Answer: Lift check valve
Lift check valves are designed specifically for vertical pipe with upward flow, where gravity helps reseat the disc when flow stops.
What is the primary advantage of a reducing tee over a standard tee combined with a reducer in piping system design?
Answer: Fewer potential leak points and reduced installed length
A reducing tee combines the branch and size reduction into one fitting, eliminating an extra joint and reducing the overall piping footprint.
Which valve is specifically designed to maintain a constant downstream pressure regardless of upstream pressure variations?
Answer: Pressure reducing valve (PRV)
A pressure reducing valve (PRV) automatically reduces upstream pressure to a preset lower downstream pressure, compensating for upstream fluctuations.