Free SC-RSC-PL Practice Questions

Question 1

After a check valve is added at a home's water meter, a gauge downstream reads 62 psi when the storage water heater is cool and gradually rises to 108 psi during reheating with all fixtures closed. An upstream gauge stays at 62 psi. Briefly opening a faucet returns the downstream pressure to 62 psi. The heater's temperature control operates normally, and no thermal-expansion device is installed. Which change addresses the cause rather than the symptom?

Accepted Answer

Add a properly sized potable-water expansion tank on the heater's cold supply, downstream of the check valve.

Answer

Install a pressure-reducing valve ahead of the heater and adjust its outlet to 50 psi.

Answer

Replace the heater's thermostat with a lower-temperature control while retaining the existing piping.

Answer

Install a listed water-hammer arrestor near the water heater's cold-water inlet connection.

Question 2

A bathroom addition has a correctly sized horizontal wet vent serving a lavatory, shower, and water closet on one floor. A kitchen sink has its own dry vent, but its drain has been connected between the lavatory connection and the most downstream bathroom fixture connection. Under the 2021 International Plumbing Code, what revision preserves the bathroom's horizontal wet-vent arrangement?

Accepted Answer

Reconnect the kitchen drain downstream of the entire wet-vented section.

Answer

Enlarge the wet-vented section to compensate for the kitchen sink's additional drainage load.

Answer

Move the kitchen sink connection upstream of the bathroom's dry-vent takeoff instead.

Answer

Increase the kitchen sink's dry-vent size and leave its drain connection in place.

Question 3

A water-distribution line is being sized for a specified design flow. At the service connection, upstream of the meter and backflow assembly, static pressure is 76 psi; pressure while supplying the design flow is 48 psi. The highest outlet is 30 ft above that connection and requires at least 20 psi residual pressure. The meter and backflow assembly together lose 6 psi at design flow. Calculated pipe-and-fitting losses are 18 psi for 1/2-inch pipe, 6 psi for 3/4-inch, 2 psi for 1-inch, and 0.8 psi for 1-1/4-inch. Use 0.433 psi per foot of elevation; no other losses apply. What is the smallest listed pipe size that meets the outlet requirement?

Accepted Answer

3/4 inch

Answer

1/2 inch

Answer

1 inch

Answer

1-1/4 inches

Question 4

A 240-volt storage water heater with two 4,500-watt, non-simultaneous elements delivers a short burst of hot water and then turns cold, even after a full recovery period. A qualified technician locks out power, verifies absence of voltage, and disconnects both leads from each element. The service specifications give a normal isolated-element resistance of 12-14 ohms. The upper element reads 12.9 ohms; the lower reads open circuit. Neither element shows continuity to its metal sheath. These findings justify replacing which component?

Accepted Answer

The lower heating element

Answer

The upper thermostat

Answer

The cold-water dip tube

Answer

The upper heating element

Question 5

In this drainage isometric, flow follows A to B to C to D to E. L connects at A, K at B, WC at C, and T at E. All fixture vents are compliant and omitted.

L ---> A
        \
K ------> B
           \
WC --------> C ---- D ---- E ---> building drain
                         /
T ----------------------/

L is a lavatory rated 1 drainage fixture unit (DFU); K is a kitchen sink rated 2 DFU; WC is a water closet rated 3 DFU with a required 3-inch fixture drain; T is a laundry tray rated 2 DFU. Segment C-D is a horizontal fixture branch. The 2021 International Plumbing Code permits 6 DFU on a 2-inch horizontal branch and 20 DFU on a 3-inch branch. What load and minimum pipe size belong on C-D?

Accepted Answer

6 DFU; 3-inch pipe

Answer

6 DFU; 2-inch pipe

Answer

8 DFU; 3-inch pipe

Answer

8 DFU; 2-inch pipe

Question 6

The purchase order specifies nominal 3/4-inch Type L hard-drawn copper water tube. At delivery, the installer checks the outside diameter with a caliper and reads the tube's identification color. Which combination matches the order exactly?

Accepted Answer

7/8-inch outside diameter with blue identification

Answer

7/8-inch outside diameter with green identification

Answer

7/8-inch outside diameter with red identification

Answer

3/4-inch outside diameter with blue identification

Question 7

A sewer-replacement crew is working in a 4-ft-6-in-deep soil trench. After rain, the foreman notices fresh cracks at the lip and pieces of soil sloughing from one wall. Spoil is 3 ft back, and a ladder is 10 ft from the workers. The competent person has not reinspected the changed conditions. The foreman's immediate instruction should be:

Accepted Answer

Leave the trench pending the competent person's reassessment and correction of the hazard.

Answer

Keep working while a spotter watches the wall for any further soil movement.

Answer

Move the spoil farther back and continue with the trench's existing wall configuration.

Answer

Treat the trench as exempt from cave-in protection because it is less than five feet deep.

Question 8

An apprentice marks a plumbing bore at midspan in an unnotched, solid-sawn floor joist. The bore is smaller than one-third of the joist's depth, and its edges will be more than 2 inches from both the top and bottom. There are no other holes. A reviewer objects solely because the bore lies in the middle third of the span. Which comment correctly applies the 2018 International Residential Code's prescriptive cutting and boring provisions?

Accepted Answer

The proposed bore complies; the middle-third prohibition applies to notches.

Answer

Move the bore into an outer third of the span before drilling it.

Answer

Reduce the bore to one-sixth of the joist depth before drilling it.

Answer

Hold the work until an engineer supplies a reinforcement detail for the bore.

Question 9

A 2-inch horizontal kitchen branch must join a 3-inch horizontal drain at a right angle and direct its discharge downstream. Both pipe axes must remain horizontal through the junction. For this connection under the 2021 International Plumbing Code, which single fitting provides the required change in direction?

Accepted Answer

A combination wye and one-eighth bend

Answer

A sanitary tee installed on its back

Answer

A wye without a separate one-eighth bend

Answer

A sanitary cross with its unused inlet capped

Question 10

An owner wants a new shower to use a conventional two-handle mixing valve because an ASSE 1017 master mixing valve already limits the hot-water distribution temperature to 118 degrees F. The project follows the 2021 International Plumbing Code. Which installation satisfies the individual shower-valve requirement?

Accepted Answer

Install an ASSE 1016 shower valve rated for the showerhead's flow, with its limit stop adjusted to 118 degrees F.

Answer

Retain the two-handle valve and lower the master mixing valve setting to 110 degrees F.

Answer

Retain the two-handle valve and add an in-line ASSE 1070 temperature-limiting device.

Answer

Retain the two-handle valve and reduce the water heater's storage setting to 118 degrees F.

Free SC-RSC-PL Practice Questions

Domain 1: General Plumbing Knowledge and Regulations

Question 1

Question 2

Domain 2: Piping, Valves, and Controls

Question 3

Domain 3: Fixtures and Equipment

Question 4

Domain 4: Water Supply

Question 5

Domain 5: Drain, Waste and Vent and Sewers

Question 6

Question 7

Domain 6: Isometric Analysis

Question 8

Domain 7: Safety

Question 9

Domain 8: Specialty Applications

Question 10

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