OH Journeyman Plumber cheat sheet

A water closet is a fixture that receives human waste and discharges it through a trap seal into a drainage system; a bidet, drinking fountain, and lavatory are also fixtures but serve different waste or potable functions.

Fixture unit (f.u.) values are assigned by drainage load: a private water closet is 3 f.u. (drainage) while a public water closet is 6 f.u.; a lavatory is 1 f.u. and a bathtub is 2 f.u.

Minimum trap seal depth is 2 inches; a trap seal deeper than 4 inches is prohibited because it resists siphonage clearing and traps debris.

Air gap is the only backflow protection considered a complete physical separation; an air gap must be at least twice the effective diameter of the discharge pipe and never less than 1 inch.

A fixture's flood-level rim is the uppermost edge of the fixture over which water would overflow; the air gap or backflow device must be installed above this rim.

An indirect waste receptor receives drainage from fixtures through an air gap or air break; a floor drain is a receptor, but a fixture drain may not connect directly to it without the required air break.

Water closet bowls must be set level and secured with a closet flange; the flange must be fastened to the floor and the closet bend connected with a gasketed or leaded joint to prevent leakage.

A lavatory is a wash basin for personal hygiene; a mop sink (service sink) is a receptor for cleaning water and must be provided where janitorial facilities are required.

Fixture spacing: water closets need at least 15 inches from the centerline to any side wall and 30 inches of clear width; the clear space in front of a water closet is at least 21 inches.

Minimum static pressure at a fixture is typically 8 psi for a flush tank water closet and 15 psi for a flushometer valve; residual pressure below these values causes poor flush performance.

Maximum pressure in a building water supply system is 80 psi; where street pressure exceeds 80 psi, a pressure-reducing valve is required.

Water supply pipe sizing uses the developed length method: developed length = actual pipe length plus equivalent length of fittings; the longest run from the meter or source to the farthest fixture governs sizing.

A pressure-reducing valve is installed downstream of the meter and must have a strainer; a bypass or relief valve protects the system from thermal expansion.

Backflow prevention: an air gap is preferred; a reduced-pressure-zone (RPZ) assembly protects against both backpressure and backsiphonage and must be tested annually.

A vacuum breaker prevents backsiphonage only and may not be used where backpressure can occur; hose-bibb vacuum breakers are required on sillcocks.

Water hammer arrestors are installed near quick-closing valves (flushometers, solenoid valves) to absorb shock; they must be accessible for maintenance.

Fixture supply sizing: a flushometer water closet requires a larger branch than a flush-tank closet; the minimum branch for a flushometer water closet is typically 1 inch.

Hot water distribution: the developed length from the water heater to the farthest fixture should be minimized; recirculation or a demand system limits wait time and wasted water.

Slope: a horizontal drainage pipe 2 1/2 inches or smaller must slope at least 1/4 inch per foot; pipes 3 inches and larger must slope at least 1/8 inch per foot.

A vent stack must extend at least 6 inches above the roof and at least 6 inches above the anticipated snow line; it must terminate at least 10 feet from an operable window or air intake.

A trap must be vented; the vent must be installed within the distance allowed by the fixture's size-commonly 5 feet for 1 1/4-inch and 1 1/2-inch traps, and 6 feet for 2-inch traps.

A soil stack carries sewage from water closets; a waste stack carries other liquid waste; a stack vent is the extension of a soil or waste stack above the highest fixture.

A vent stack must be sized to handle the air it supplies; a common vent may serve two fixtures at the same level, but the fixtures must be on the same floor and the vent must be properly sized.

A cleanout is required at the base of each stack, at the end of each horizontal drain run, and at each change in direction greater than 45 degrees; cleanouts must be accessible.

A backwater valve is required on a drainage branch subject to backflow from a public sewer; it must be installed so it can be serviced and must be a normally open type.

A horizontal wet vent may serve a bathroom group where the wet vent is sized and the fixtures are on the same floor; the wet vent must be at least 2 inches in diameter for a water closet.

Drainage fixture units convert to pipe size using tables: a 3-inch building drain handles about 42 f.u. at 1/8-inch slope; a 4-inch drain handles about 216 f.u. at 1/8-inch slope.

The Ohio Plumbing Code is based on the International Plumbing Code (IPC) with Ohio amendments; local jurisdictions may adopt additional amendments, so always verify the local authority having jurisdiction (AHJ).

A permit is required before installing, altering, or repairing a plumbing system; the AHJ inspects rough-in and final work, and work must not be concealed before rough-in inspection approval.

A plumbing license is required to perform plumbing work in Ohio; a journeyman plumber works under a licensed plumbing contractor, and an apprentice works under direct supervision.

Code definitions control enforcement: a "fixture branch" is the pipe between a fixture and the fixture drain; a "building drain" is the lowest pipe inside the building that receives soil and waste.

The code requires potable water to be protected from contamination; cross-connections must be eliminated or controlled with an approved backflow prevention device.

Vent termination, trap seal protection, and fixture clearances are code requirements, not preferences; an inspector may require corrections where these are not met.

A code violation may result in a stop-work order, failed inspection, or permit revocation; correcting the violation and re-inspection are required before occupancy.

The AHJ has authority to interpret code provisions; written interpretations and local amendments should be requested in writing when a design is unusual.

Before soldering, purge the pipe of water and open the system to atmosphere; trapped water or sealed air prevents solder from flowing and can cause a blowout.

Lead exposure: use lead-free solder (no more than 0.2 percent lead) for potable water; wear gloves and eye protection, and ventilate when soldering or working with leaded joints.

Confined spaces require atmospheric testing, ventilation, and a permit; never enter a sewer manhole or pit without testing for oxygen, hydrogen sulfide, and combustible gas.

Pipe wrenches: a straight pipe wrench grips round pipe; a chain wrench is used on large pipe or where a wrench will not fit; never use a pipe wrench on chrome or finished surfaces without protection.

A tubing cutter leaves a burr-free square end; ream the inside of copper tube after cutting to prevent turbulence and erosion-corrosion.

Press tools and crimp tools require the correct jaw or ring for the pipe size and material; an uncalibrated press tool can produce a joint that fails under pressure.

Electrical safety: use ground-fault circuit interrupter protection on temporary power, and keep cords away from water; lock out and tag out before working on a circuit.

Ladder safety: maintain a 4-to-1 slope for extension ladders, secure the top, and keep three points of contact; never stand on the top two rungs.

Personal protective equipment for plumbing includes safety glasses, gloves, hearing protection when using power tools, and a respirator when cutting cast iron or working with solvents.

Copper tube types: Type K is heaviest (green), Type L is medium (blue), and Type M is lightest (red); Type M is not permitted underground or for some high-pressure applications.

PEX is joined with crimp, clamp, or press fittings; each fitting system is manufacturer-specific and must not be mixed. PEX must be protected from UV light and from freezing.

PVC is used for drainage and venting and is joined with solvent cement; CPVC is used for hot water and is joined with CPVC cement, not PVC cement.

Cast iron soil pipe is joined with no-hub couplings or lead-oakum joints; no-hub couplings require a torque wrench set to the manufacturer's specification.

Galvanized steel pipe is joined with threaded fittings; it is not recommended for potable water because of corrosion and lead concerns in older installations.

A dielectric union separates dissimilar metals (copper and steel) to prevent galvanic corrosion; a brass fitting may also serve as a transition.

Fittings: a sanitary tee has a curved branch for drainage flow; a wye (Y) fitting provides a smoother direction change; a combination wye-and-eighth-bend is used for horizontal-to-vertical transitions.

A trap primer maintains the trap seal of a floor drain by supplying a small amount of water; it must be connected to a potable water source with backflow protection.

Pipe support spacing: copper tube 1 inch and smaller is supported at least every 6 feet; PVC schedule 40 pipe 1 1/2 inches and smaller is supported at least every 4 feet.

Pipe volume: volume = area x length. Area of a circle = pi x r squared; for a 4-inch pipe, r = 2 inches, so area = 3.1416 x 4 = 12.57 square inches.

Convert cubic inches to gallons: 1 gallon = 231 cubic inches. A 4-inch pipe 10 feet long holds 12.57 x 120 = 1,508 cubic inches, or about 6.5 gallons.

Slope calculation: drop = slope x run. A 3-inch pipe at 1/8 inch per foot over 20 feet drops 2.5 inches.

Fixture unit conversion: total drainage fixture units are summed and then converted to pipe size using the code table; do not add water supply fixture units and drainage fixture units together.

Developed length = measured pipe length + equivalent length of fittings. Equivalent length values come from tables and depend on fitting type and size.

Pressure and head: 1 psi = 2.31 feet of water column. A 20-foot rise of water produces about 8.7 psi of static pressure.

Water heater sizing: approximate demand = number of fixtures x flow rate x diversity factor; a storage tank should be sized to meet peak demand without exceeding recovery capacity.

Measure twice: use a tape measure and a level; verify square and plumb before cutting, and allow for fitting takeout (the distance a pipe must be shortened to seat in a fitting).

Unit conversions: 1 foot = 12 inches; 1 cubic foot = 7.48 gallons; 1 inch = 25.4 millimeters; 1 gallon of water weighs about 8.34 pounds.

A plumbing system has four parts: water supply, fixtures, drainage, and venting. Design must balance pressure, flow, and drainage capacity.

Sizing the water service: determine the total water supply fixture units, convert to probable demand in gallons per minute, then select pipe size based on velocity limits (typically 5-8 feet per second).

A building drain runs horizontally to the building sewer; a building sewer runs from the building to the public sewer or private disposal system and must be sized for the total drainage load.

Vent design: each fixture trap must be protected by a vent; a stack vent serves fixtures on a stack, and a vent stack serves the drainage stack.

Water heater installation: a temperature and pressure relief valve is required, piped to a safe discharge point; the discharge pipe must not be trapped or reduced in size.

A recirculating hot water system uses a return line and pump to keep hot water at the fixtures; it reduces wait time and water waste but requires insulation on hot and return lines.

Expansion: PEX and CPVC require allowance for thermal expansion; long straight runs need expansion loops or offsets to prevent stress on fittings.

Testing: a drainage system is tested with water or air before concealment; a water supply system is tested at working pressure plus 50 psi, or as required by the AHJ, for at least 15 minutes.

Installation sequence: rough-in (piping and fittings) is inspected before closing walls; then fixtures, trim, and final connections are installed and the final inspection is requested.