10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
The CO-JP exam has 100 questions and runs 4 hours.
These 10 free CO-JP questions are organized by exam domain, so you can see how each part of the Colorado Journeyman Plumber License Exam blueprint is tested. Reveal the answer and explanation under each question.
A landscape irrigation system injects fertilizer into its water supply. A downstream booster pump can raise irrigation pressure above potable-supply pressure, and the connection remains continuously pressurized. Which device is suitable for protecting the potable supply against this combination of hazard and operating conditions?
Correct answer: A - Reduced-pressure-principle backflow prevention assembly
At a lavatory rough-in, a 1-1/2-inch trap arm runs 5 feet to its individual dry vent at a uniform slope of 1/4 inch per foot. The vent takeoff is above the drain's centerline, but the dry vent turns horizontal only 4 inches above the lavatory's flood-level rim. This is not an island-fixture vent. Which single change corrects the venting defect?
Correct answer: C - Raise the horizontal vent offset to 8 inches above the rim.
Six floor-outlet water closets connect horizontally to a circuit-vented branch on one floor. Its circuit vent connects between the two most upstream fixture drains. The branch enters a drainage stack that also receives upper-floor discharge. Pipe sizes, slope, and trap-to-vent distances comply. What additional vent connection is required for this layout?
Correct answer: C - A relief vent between the last downstream fixture drain and the stack.
At a health club, a public handwashing lavatory delivers 118°F at its hottest setting. A shower also delivers 118°F with its handle against the maximum-temperature stop. The lavatory has a listed temperature-limiting device, and the shower has the required automatic compensating valve. Based on the delivery-temperature limits for these fixtures, which adjustment is required?
Correct answer: A - Lower the lavatory setting to 105°F; leave the shower setting unchanged.
A Colorado hanger schedule specifies 6-inch horizontal PVC drainage pipe supported at intervals of 3 feet 6 inches, using 3/8-inch steel hanger rods. The pipe manufacturer imposes no more restrictive spacing requirement, and the attachments and hangers are otherwise suitable. Which finding should the reviewer make about the proposed spacing and rod diameter?
Correct answer: D - Only the rod diameter fails; use at least 1/2 inch.
A roof drainage area has a horizontal projection of 3,600 square feet and an actual sloped surface of 4,800 square feet. A 1,000-square-foot vertical wall diverts rain onto this roof. The approved design rainfall is 3.5 inches per hour. Use Q = 0.0104 x A x R, where Q is gpm, A is the effective area in square feet, and R is rainfall in inches per hour. Complete drain assemblies are rated at the flows listed below at the permitted ponding head, with adequate downstream piping. What is the smallest listed assembly that can serve this area?
Correct answer: B - 160 gpm
A new commercial building has basement fixtures that drain by gravity to a public sewer. Both the basement floor and those fixtures' flood-level rims are below the next upstream manhole cover. The upper floor and all its fixture rims are above that cover. Where should the required backwater protection be provided?
Correct answer: D - In the basement branch, before it joins the upper-floor drainage.
A plumber must join a 2-inch horizontal sink branch to a 4-inch horizontal sanitary drain. The branch approaches the drain at 90 degrees in plan, and both pipes are horizontal at the junction. Which single fitting accommodates that angle and is permitted for this drainage connection?
Correct answer: C - A combination wye and one-eighth bend
The waste pipe from a restaurant's food-preparation sink terminates inside a trapped and vented floor sink. Its open end is above the standing water but below the floor sink's flood-level rim. There is no sealed connection between the two pipes. How should this connection be classified for food-protection purposes?
Correct answer: A - It is an air break; this food-preparation sink requires an air gap.
A pressure gauge downstream of a pressure-reducing valve and check valve remains at 62 psi during an hour with the water heater off. With every heating cycle, pressure gradually rises to 96 psi while all faucets are closed. A small hot-water draw immediately returns it to 62 psi. Street pressure remains steady, and no quick-closing valves operate during the rise. Which condition best accounts for this pattern?
Correct answer: B - Thermal expansion in a closed system with inadequate expansion capacity
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