Pool & Spa Systems Design & Operation Flashcards
7 cards from real CPI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Pool & Spa Systems Design & Operation flashcards as text
Which pool design feature creates a visual edge where water appears to spill off into the horizon?
Answer: Infinity or vanishing edge
An infinity (vanishing or negative) edge pool has one or more walls set slightly below the water level so water overflows continuously into a catch basin below.
What is the purpose of a surge tank or balance tank in a commercial pool system?
Answer: To absorb displaced water when bathers enter and maintain a consistent water level at the overflow
A surge/balance tank collects overflow water when bathers displace it and returns it to the pool via the recirculation pump, maintaining a constant operating water level.
A pool designed with a 'zero-entry' or 'beach entry' feature must have anti-entrapment drain covers that:
Answer: Cover all suction outlets including any in the sloped entry area
ANSI/APSP and VGBA requirements mandate compliant anti-entrapment drain covers on all suction outlets regardless of depth, including the shallow sloped entry.
What is the typical operating pressure range for a properly functioning sand filter?
Answer: 8–15 PSI
A clean sand filter typically operates between 8 and 15 PSI; the filter should be backwashed when pressure rises 8–10 PSI above the clean operating baseline.
Which material is commonly used for underground pool plumbing due to its chemical resistance and ease of gluing?
Answer: Schedule 40 PVC
Schedule 40 PVC is the standard material for pool plumbing because it resists chlorine and chemical corrosion, is lightweight, and can be solvent-welded (glued) for watertight joints.
A pool shell that is gunite or shotcrete must cure for a minimum period before plastering primarily because:
Answer: Premature plastering traps moisture that causes cracking and bond failure
Shotcrete/gunite must be kept moist (wet-cured) for at least 28 days so it reaches full compressive strength; plastering too soon over uncured shell causes delamination and surface cracks.
What does 'variable speed pump' technology improve compared to single-speed pumps?
Answer: Energy efficiency by matching motor RPM to actual flow demand
Variable speed pumps use EC motors that can run at reduced RPM during low-demand periods, dramatically cutting energy consumption since power draw decreases with the cube of speed reduction.