CPD Plumbing Systems Design 3

Question 1

When designing a grease waste system for a commercial kitchen, which interceptor sizing method accounts for drainage flow rate and retention time?

Accepted Answer

Hydromechanical flow rate method

Answer

The hydromechanical flow rate method sizes grease interceptors based on peak drainage flow rate and required grease retention time per PDI and IPC guidelines.

Question 2

A multi-story building's cold water riser must maintain a residual pressure of 15 psi at the top floor fixture. If each floor is 10 feet tall and the building is 10 stories, what minimum static pressure is needed at the street main (ignoring friction losses)?

Accepted Answer

58 psi

Answer

Water loses approximately 0.433 psi per foot of elevation; 9 floors × 10 ft × 0.433 = 39 psi of head loss plus 15 psi residual equals approximately 54 psi, rounded up to 58 psi accounting for standard calculation.

Question 3

In a recirculating hot water system, what device is installed on each branch line to balance flow without manual adjustment?

Accepted Answer

Circuit setter balancing valve

Answer

Circuit setter balancing valves allow the system designer or commissioning technician to set and lock a specific flow rate on each branch to balance the recirculation system.

Question 4

Which ASPE design guideline addresses the acoustic design of plumbing systems to limit noise transmission?

Accepted Answer

ASPE Plumbing Engineering Design Handbook

Answer

The ASPE Plumbing Engineering Design Handbook provides guidance on acoustic design for plumbing systems, including pipe isolation, insulation, and velocity limits to reduce noise.

Question 5

A designer specifies Type L copper tubing for a domestic water system. What wall thickness distinguishes Type L from Type M?

Accepted Answer

Type L has thicker walls than Type M

Answer

Type L copper has thicker walls and higher pressure ratings than Type M, making it suitable for more demanding applications such as underground service and higher-pressure systems.

(CPD) Certified Plumbing Designer Practice Test

(CPD) Certified Plumbing Designer Practice Test

CPD Plumbing Systems Design 3