MT Journeyman Plumber flashcards

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

Maximum flush volume, water closet

The 2021 UPC limits water closets to 1.6 gallons per flush. Older 3.5 gpf and 5 gpf toilets may not be installed in new work or replacement unless an exception applies.

Drainage slope, 2-1/2 inch and smaller

Horizontal drainage pipe 2-1/2 inches and smaller must slope at 1/4 inch per foot. This is the standard fall for fixture branches, lavatory drains, and small building drains.

Drainage slope, 3 inch and larger

Horizontal drainage pipe 3 inches and larger may slope at 1/8 inch per foot. Larger pipe carries more fixture units, so the reduced slope still maintains adequate scouring velocity.

Drainage water test

The drainage and vent system is filled with water to at least 10 feet of head at the lowest point, or to the highest point of the system, and held for 15 minutes before concealment.

Drainage air test

An alternative to the water test: the system is charged with 5 psi of air and held for 15 minutes with no drop on the gauge. Used where water testing is impractical.

Water supply test pressure

Water distribution piping is tested at working pressure or 100 psi, whichever is greater, for at least 1 hour with no leaks before the piping is concealed.

Vent termination height

A vent must extend at least 6 inches above the roof surface and be at least 10 feet from any window, door, or air intake, or 2 feet above such openings.

Trap seal depth

The vertical distance between the crown weir and the top of the trap dip must be between 2 and 4 inches. A seal outside this range is prone to evaporation or siphonage.

Trap arm length limit

The distance from the trap weir to the vent connection is limited by pipe size: about 5 feet for 1-1/2 inch, 6 feet for 2 inch, and 10 feet for 3 inch.

Water closet DFU

A water closet is rated 3 drainage fixture units regardless of flush volume. This value is used to size the building drain, sewer, and branch lines.

Lavatory DFU and WSFU

A lavatory is 1 drainage fixture unit and 1 water supply fixture unit. These low values reflect intermittent, small-volume use compared with a water closet.

Bathtub DFU and WSFU

A bathtub is 2 drainage fixture units and 1.4 water supply fixture units. A shower is also 2 DFU and 1.4 WSFU, since both discharge similar volumes.

Kitchen sink fixture units

A kitchen sink is 2 drainage fixture units and 1.4 water supply fixture units. A dishwasher connected to the sink adds its own demand and requires an indirect waste or air gap.

Washing machine fixture units

A washing machine is 2 drainage fixture units and 1.4 water supply fixture units. Laundry tubs carry the same values and are counted separately when both are installed.

Fixture unit definition

A fixture unit expresses the probable discharge a fixture places on the drainage system, based on flow rate and duration of use. DFU sizes drains; WSFU sizes supply.

Water closet clearance

A water closet requires at least 15 inches from its centerline to a side wall and at least 21 inches of clear space in front of the bowl for use and service access.

Cleanout locations

Cleanouts are required at the base of each stack, at the end of each horizontal drain, and at intervals not exceeding 100 feet in horizontal runs, and must remain accessible.

Backwater valve requirement

A backwater valve is required where the building drain is below the level of the public sewer or where flooding of the building drain is possible, to prevent sewage backup.

Relief valve discharge

A water heater temperature and pressure relief valve must discharge through a pipe terminating within 6 inches of the floor or at another safe point, with no thread or cap on the end.

Shower valve temperature limit

Shower and tub/shower valves must be pressure-balancing or thermostatic, and the maximum water temperature delivered at the fixture is limited to 120 degrees F to prevent scalding.

Lead-free definition

For potable water piping, solder, and flux, lead-free means not more than 0.25 percent lead by weight. Lead-based solder is prohibited in potable water systems.

Permit exemptions

Permits are not required for minor repairs such as stopping leaks, clearing stoppages, or replacing exposed fixture fittings. New installation, alteration, or replacement of piping requires a permit.

Alternate materials approval

The code official may approve an alternate material or method if it is equivalent in quality, strength, effectiveness, fire resistance, durability, and safety, and may require tests to verify compliance.

Montana licensing authority

The Montana Department of Labor and Industry administers plumbing licensing and adopts the Montana Plumbing Code by administrative rule. Local jurisdictions may add stricter requirements.

Master plumber role

A master plumber license is required to contract for plumbing work, obtain permits, and supervise journeymen and apprentices. Journeymen may work only under a master's supervision.

Apprentice supervision

Apprentices must be registered with the department, enrolled in a training program, and work under the direct supervision of a licensed journeyman or master plumber while accumulating hours.

Montana continuing education

License renewal requires completing continuing education hours set by department rule, with approved topics including code updates, safety, and technical training, and records kept for audit.

Montana permit and inspection

Plumbing permits must be obtained from the local jurisdiction before work begins, and inspections must be requested at rough-in and final stages; occupancy requires final plumbing approval.

Building drain versus sewer

The building drain is the lowest piping of the drainage system inside the building; the building sewer runs from the building drain to the public sewer or private disposal system.

Common vent

A common vent serves two fixtures on the same floor when they are within the allowed distance and the vent is sized for the combined fixture unit load of both fixtures.

Grease interceptor

Grease interceptors are required for commercial kitchens and fixtures discharging grease-laden waste, sized by flow rate and retention time, and must be accessible for cleaning.

Indirect waste and air gap

Food service sinks, sterilizers, and dishwashers must discharge through an air gap of at least twice the waste pipe diameter, never directly connected to the drainage system.