MI Plumber flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Drainage Fixture Unit

A unit value assigned to a fixture representing its probable rate of discharge into the drainage system, with one fixture unit equal to approximately 1 gallon per minute.

Building Drain

The lowest piping of a drainage system that receives soil, waste, and other drainage inside the building walls and conveys it to the building sewer, ending 30 inches outside the wall.

Approved

Accepted by the code official as meeting the requirements of the plumbing code, often evidenced by listing or labeling by an approved third-party testing agency.

Slope for Small Drainage Pipe

Horizontal drainage pipe 2-1/2 inches and smaller must slope at 1/4 inch per foot; pipe 3 inches and larger may slope at 1/8 inch per foot.

Sanitary Tee

A drainage fitting that connects a horizontal branch to a vertical stack and directs flow downward with the stack, used only where the branch turns downward.

Long-Sweep Bend

A 90-degree drainage fitting with an extended sweep radius, used where a horizontal drainage line changes direction to reduce turbulence and prevent clogging.

Cleanout Requirements

Cleanouts are required at the upper end of horizontal drains, at the base of stacks, and within 5 feet of the building sewer, and openings must stay accessible and gas-tight.

Trap Arm Length

The horizontal distance from a trap weir to its vent, limited by pipe size and slope; for example, a 2-inch trap arm may not exceed 8 feet at 1/4 inch per foot.

Dry Vent

A vent carrying only air that must rise vertically, or at no more than 45 degrees from vertical, until it reaches 6 inches above the fixture flood level rim.

Vent Terminal Height

A vent stack must extend at least 6 inches above the roof surface, or 7 feet where the roof is used for purposes other than weather protection.

Wet Vent

A pipe that serves as both the drain for one fixture and the vent for another; limited to fixtures on the same floor and sized per code tables.

Residual Water Pressure

The minimum flowing pressure required at fixture outlets, generally 8 psi; static pressure above 80 psi requires a pressure reducing valve on the system.

Pressure Reducing Valve

A device installed on the water service where static pressure exceeds 80 psi to reduce it to a safe level, with provisions for thermal expansion.

Air Gap Backflow Prevention

The unobstructed vertical distance between a water supply outlet and the flood level rim of the fixture it serves, providing the highest degree of backflow protection.

Water Closet Clearance

A water closet must be at least 15 inches from its centerline to any side wall and have at least 21 inches of clear space in front of the bowl.

Shower Receptor Minimum Size

A shower compartment must measure at least 30 inches by 30 inches inside, have a finished curb, and drain through a minimum 2-inch trapped drain.

Gravity Water Closet Flush Volume

Storage-type water closets are limited to 1.6 gallons per flush by federal efficiency standards, with several states requiring 1.28 gallons per flush.

Trap Seal Depth

The vertical distance between the trap weir and the top of the trap dip, required to be at least 2 inches and not more than 4 inches.

Grease Interceptor

A receptacle installed to intercept fats, oils, and grease from food service fixtures before discharge, sized by code formulas and requiring periodic pumping and maintenance.

Prohibited Traps

S-traps, bell traps, crown vents, traps with moving parts, and traps for fixtures with integral traps such as water closets are prohibited by the plumbing code.

Secondary Roof Drain

On a roof with a parapet that uses roof drains, a secondary drain or scupper must be installed at least 2 inches above the primary drain to handle overflow.

Roof Drain Sizing Basis

Roof drain and leader sizes are chosen from code tables using the roof area served and the 100-year, one-hour rainfall rate for the location.

Storm Sewer Separation

Storm drainage must be collected and conveyed separately from sanitary drainage unless the authority having jurisdiction specifically approves a combined sewer connection.

Offset Travel Multiplier 45 Degrees

For a 45-degree offset, travel equals the offset dimension multiplied by 1.414, and the offset equals the travel multiplied by 0.707.

Head Pressure Conversion

One pound per square inch equals 2.31 feet of water column, so a column 10 feet high produces about 4.33 psi at its base.

Rainfall to Gallons Per Minute

Roof runoff in gallons per minute equals the roof area in square feet multiplied by the rainfall rate in inches per hour and by 0.0104.

Bathroom Group Fixture Units

A bathroom group containing a water closet, a lavatory, and a bathtub or shower is rated at 6 drainage fixture units for sizing purposes.

Trench Protective System Threshold

Excavations 5 feet deep or more require a protective system such as sloping, shoring, or a trench box, unless the excavation is made entirely in stable rock.

Ladder Extension Above Landing

Portable ladders must extend at least 3 feet above the landing and be set with the base one-quarter of the working height away from the wall.

Sediment Trap

A drip leg installed at the appliance connection that collects dirt, pipe scale, and debris before it can enter and damage the gas controls.

Gas Piping Bonding

Fuel gas piping must be made electrically continuous and bonded to the grounding electrode system of the premises wiring to prevent dangerous arcing.

Appliance Connector Length

A flexible gas appliance connector may not exceed 6 feet in length and must not pass through walls, floors, ceilings, or concealed spaces.