ASSE 5150 cheat sheet

The plumbing code regulates the water supply, sanitary drainage, venting, storm drainage, and fixture systems within a building; the mechanical code governs HVAC, refrigeration, and related equipment.

A fixture unit (FU) is a dimensionless measure of the probable load a fixture places on the drainage or water supply system; 1 FU equals 1 cubic foot per minute (cfm) of drainage flow or 1 gallon per minute (gpm) of water supply.

The building drain extends from the building to the building sewer; the building sewer begins at the building foundation and runs to the public sewer or private disposal system.

The drainage system must be designed to convey the peak discharge without surcharge; the water supply system must deliver the peak demand at the minimum residual pressure required by the code.

The minimum size of a building water service is 3/4 inch; the minimum size of a building drain is 4 inches for buildings with more than one water closet.

Stack vents and vent stacks must extend at least 6 inches above the roof and at least 12 inches above any roof surface used for other purposes; the vent terminal must be at least 10 feet from any lot line, opening, or air intake.

The code establishes a minimum trap arm length and a maximum developed length based on pipe diameter; the trap arm must be at least two pipe diameters in length and the fixture must be vented within the prescribed distance.

A plumbing permit is required for the installation, alteration, repair, or replacement of a plumbing system; minor repairs and replacement of fixtures may be exempted by the authority having jurisdiction.

The water service pipe must be sized to deliver the peak demand at a residual pressure of at least 8 psi at the highest fixture; the minimum static pressure at the service entry is typically 20 psi.

The minimum size of a water service is 3/4 inch; the minimum size of a water distribution pipe is 1/2 inch, except that a 3/8-inch pipe may serve a single fixture with a low demand.

The water distribution system must be designed to limit the velocity of flow to 8 feet per second in metallic pipe and 5 feet per second in plastic pipe to reduce noise and erosion.

Pressure-reducing valves are required when the static pressure exceeds 80 psi; a pressure-relief valve or thermal expansion tank is required on a closed system to prevent excessive pressure from thermal expansion.

The minimum size of a water heater drain pan is 1.5 inches deep and must be at least 3 inches larger in diameter than the water heater; the pan must be piped to a drain with a minimum 3/4-inch pipe.

The water supply system must be protected against backflow by an air gap, a reduced pressure principle backflow preventer, a double check valve assembly, or a vacuum breaker, depending on the degree of hazard.

The minimum diameter of a water service for a single-family dwelling is 3/4 inch; the minimum diameter of a water meter is 5/8 inch.

The water distribution system must be tested at a pressure of at least 100 psi for at least 60 minutes; the pressure must not drop more than 5 psi during the test.

The slope of a horizontal drainage pipe must be at least 1/4 inch per foot for pipe sizes 2 inches and smaller, and at least 1/8 inch per foot for pipe sizes 3 inches and larger.

The minimum size of a building drain is 4 inches; the minimum size of a building sewer is 4 inches; the minimum size of a soil stack is 3 inches.

A horizontal drainage pipe must be supported at intervals not exceeding 4 feet for cast iron, 4 feet for plastic, and 10 feet for copper; vertical pipe must be supported at each story.

A vent stack must extend at least 6 inches above the roof and at least 12 inches above any roof surface used for other purposes; the vent terminal must be at least 10 feet from any lot line, opening, or air intake.

The maximum developed length of a trap arm is based on the pipe diameter: 1-1/2 inch = 6 feet, 2 inch = 8 feet, 3 inch = 12 feet, and 4 inch = 16 feet, unless the fixture is vented by a circuit vent or other approved method.

A cleanout must be installed at the base of each soil stack, at the building drain, and at intervals not exceeding 100 feet in horizontal drainage pipes; cleanouts must be accessible.

Storm drainage must be sized to handle the rainfall intensity for the area; the minimum size of a storm drain is 3 inches; the slope must be at least 1/8 inch per foot for pipe sizes 3 inches and larger.

A backwater valve is required on the building sewer when the building drain is below the elevation of the public sewer; the valve must be accessible for maintenance.

The minimum water closet flush volume is 1.6 gallons per flush; the minimum urinal flush volume is 1.0 gallon per flush; the minimum showerhead flow rate is 2.5 gallons per minute at 80 psi.

The minimum lavatory faucet flow rate is 2.2 gallons per minute at 60 psi; the minimum kitchen sink faucet flow rate is 2.2 gallons per minute at 60 psi.

The water heater must be installed with a temperature and pressure relief valve; the relief valve must be piped to a safe location and must not be connected to the drainage system without an air gap.

The water heater must be secured to resist seismic forces; the strapping must be installed at the upper and lower thirds of the tank and must be capable of resisting a horizontal force of 0.5 times the weight of the water heater.

The minimum size of a water heater drain pan is 1.5 inches deep and must be at least 3 inches larger in diameter than the water heater; the pan must be piped to a drain with a minimum 3/4-inch pipe.

A fixture must be provided with a trap; the trap must be of the same size as the fixture drain; the trap seal must be at least 2 inches and not more than 4 inches deep.

The minimum clearance between a fixture and a wall or partition is 15 inches from the centerline of the fixture to the wall; the minimum clearance between two fixtures is 30 inches center-to-center.

The water heater must be provided with a shutoff valve on the cold water supply; a check valve or backflow preventer is required on the cold water supply to prevent thermal expansion from backflowing into the public water system.

A cross-connection is any actual or potential connection between a potable water system and any nonpotable source; backflow is the reversal of flow in a water system.

Backsiphonage is backflow caused by negative pressure in the supply system; backpressure is backflow caused by pressure in the nonpotable system exceeding the supply pressure.

An air gap is the most effective backflow prevention device; it must be at least twice the diameter of the supply pipe and never less than 1 inch.

A reduced pressure principle backflow preventer (RPZ) is required for high-hazard applications; it consists of two independently acting check valves and a differential pressure relief valve.

A double check valve assembly (DCVA) is used for low-hazard applications; it consists of two independently acting check valves and must be tested annually.

A pressure vacuum breaker (PVB) must be installed at least 12 inches above the highest downstream outlet; it is used for low-hazard applications.

An atmospheric vacuum breaker (AVB) must be installed at least 6 inches above the highest downstream outlet; it cannot be used under continuous pressure.

Backflow prevention devices must be tested at the time of installation and at least annually thereafter; the test results must be filed with the authority having jurisdiction.

The water distribution system must be tested at a pressure of at least 100 psi for at least 60 minutes; the pressure must not drop more than 5 psi during the test.

The drainage system must be tested by a water test, an air test, or a smoke test; the water test must be conducted by filling the system with water to a depth of at least 10 feet above the highest point of the system.

The air test for the drainage system must be conducted at a pressure of at least 5 psi for at least 15 minutes; the pressure must not drop more than 1 psi during the test.

The building sewer must be tested by a water test or an air test; the water test must be conducted by filling the sewer with water to a depth of at least 10 feet above the highest point of the sewer.

The final inspection must be conducted after all plumbing work is complete and before the system is placed in operation; the inspection must verify that all fixtures, appurtenances, and devices are installed in accordance with the approved plans.

Plan review must verify that the plumbing system complies with the code; the review must include the sizing of the water supply and drainage systems, the venting system, and the backflow prevention devices.

The authority having jurisdiction may require additional inspections for special plumbing systems, such as medical gas systems, grease interceptors, and private sewage disposal systems.

The permit holder must notify the authority having jurisdiction when the work is ready for inspection; the notice must be given at least 24 hours before the inspection.

A plumbing permit is required for the installation, alteration, repair, or replacement of a plumbing system; minor repairs and replacement of fixtures may be exempted by the authority having jurisdiction.

The permit application must include a description of the work, the location, the name and address of the owner, and the name and license number of the plumber.

The permit must be posted on the job site; the permit is valid for a period of 180 days from the date of issuance; the permit may be extended for an additional 180 days upon written request.

The authority having jurisdiction may revoke a permit if the work is not performed in accordance with the approved plans or the code; the permit holder must be given notice and an opportunity for a hearing.

A certificate of occupancy must not be issued until the plumbing system has passed the final inspection; the certificate of occupancy is required before the building may be occupied.

The code official may issue a stop-work order if the work is being performed in violation of the code; the stop-work order must be in writing and must state the reason for the order.

A variance may be granted by the board of appeals if the strict application of the code would cause undue hardship; the variance must not compromise the health, safety, or welfare of the public.

The code official may assess penalties for violations of the code; the penalties may include fines, imprisonment, or both; each day of violation may be considered a separate offense.

The minimum thickness of a protective sleeve for a pipe passing through a concrete wall is 1/2 inch; the sleeve must be at least 2 inches larger in diameter than the pipe.

The minimum distance between a water service pipe and a sewer pipe is 10 feet horizontally or 18 inches vertically; the water pipe must be above the sewer pipe if the vertical separation is less than 18 inches.

The minimum distance between a water heater and combustible material is 6 inches for a gas-fired water heater; the water heater must be installed on a noncombustible floor or on a stand.

The minimum size of a grease interceptor is 10 gallons per minute for a single-compartment sink; the grease interceptor must be installed downstream of all fixtures that discharge grease.

The minimum size of a medical gas pipe is 1/2 inch; the pipe must be installed by a certified installer and must be tested in accordance with NFPA 99.

The minimum size of a fuel gas pipe is 1/2 inch; the pipe must be installed in accordance with the fuel gas code and must be tested at a pressure of at least 1.5 times the maximum working pressure.

The minimum size of a rainwater harvesting system pipe is 3/4 inch; the system must be protected against backflow and must be tested for leaks before being placed in operation.

The minimum size of a private sewage disposal system pipe is 4 inches; the system must be designed by a licensed engineer and must be approved by the authority having jurisdiction.