OK Plumber cheat sheet

Oklahoma issues apprentice, journeyman, and master plumber credentials through the Construction Industries Board; plumbing contracting must be performed by or under a licensed plumbing contractor.

The Oklahoma Uniform Plumbing Code is the statewide adopted code built on the International Plumbing Code; local amendments may be stricter, but not weaker, than the state minimum.

A permit is required before work starts: rough-in inspection happens before piping is covered, and final inspection happens after fixtures and appliances are set and tested.

The authority having jurisdiction (code official) may approve alternate materials and methods, require tests, and issue written interpretations that control on the job.

Developed length is the pipe length measured along the centerline plus the equivalent length of fittings and valves, and it drives both drain and water pipe sizing.

A drainage fixture unit (DFU) is a load value assigned by fixture type; a water closet is typically 3 DFU and a lavatory 1 DFU.

All pipe, fittings, and fixtures must be listed and marked to a recognized standard (ASTM, NSF, CSA); unlisted or unmarked material cannot be installed.

Work without a required permit or license is subject to stop-work orders, fines, and discipline of the credential.

Static pressure at fixtures must not exceed 80 psi; where the building supply is higher, a pressure-reducing valve is required.

Water service pipe is buried at least 12 inches below grade and below local frost depth, and must be protected from freezing and mechanical damage.

Water distribution piping is tested with water at working pressure before concealment and must hold with no visible leaks.

Water hammer arrestors, listed to a recognized standard, are required at quick-closing valves such as those serving dishwashers, washing machines, and flush valves.

A water heater temperature and pressure relief valve is set at 210 degrees F / 150 psi maximum and discharges full size, by gravity, unthreaded, ending not more than 6 inches above the floor or outside the building.

Where a check valve, pressure-reducing valve, or backflow preventer creates a closed system, thermal expansion control such as an expansion tank is required.

An air gap provides the highest degree of backflow protection; hose bibbs and sillcocks need an approved vacuum breaker.

Size water piping from water supply fixture units, developed length, and available pressure; design velocities are commonly held near 8 fps cold and 5 fps hot to limit noise and erosion.

Trap seal depth must be at least 2 inches and not more than 4 inches.

The developed length from the fixture outlet to the trap weir may not exceed 24 inches vertically or 30 inches horizontally.

Building drain slope: 1/4 inch per foot for pipe 2-1/2 inches and smaller, and 1/8 inch per foot for 3-inch and larger pipe.

Cleanouts are required at the base of each stack, at the building sewer, at changes of direction greater than 45 degrees, and at each 100 feet of aggregate horizontal run.

A vent must be at least 1-1/4 inches in diameter and not smaller than one-half the diameter of the drain it serves.

A vent stack terminates outdoors at least 6 inches above the roof surface and at least 10 feet horizontally from any lot line.

Each fixture gets its own trap: double trapping, S-traps, and unvented trap arms are prohibited.

PVC DWV pipe is supported horizontally at intervals not exceeding 4 feet, and vertical stacks are supported at the base and at each story.

Water closets must not exceed 1.6 gallons per flush and urinals must not exceed 1.0 gallon per flush; fixtures must be listed to those volumes.

Faucet flow limits: lavatory and kitchen faucets 2.2 gpm at 60 psi; showerheads 2.5 gpm at 80 psi.

A clothes washer standpipe is at least 2 inches in diameter and terminates between 18 and 42 inches above the trap weir.

Dishwasher discharge connects upstream of the trap through an air gap or high loop to prevent backflow into the appliance.

Floor drains require a trap, and seldom-used floor drains require an automatic trap primer to maintain the seal.

An air gap is the unobstructed vertical distance between the supply outlet and the flood level rim, and must be at least twice the effective opening of the outlet.

Fixtures must be accessible, level, securely fastened, and sealed watertight to the drain with an approved gasket or sealant.

A water heater needs a T&P valve, a drain pan where leakage would cause damage, and a drain line run to an approved location.

Approved gas materials include schedule 40 black steel, listed copper, listed corrugated stainless steel tubing (CSST), and listed plastic; all must be marked and listed.

Gas pipe is sized from the total connected Btu/h load and the longest run length using the code sizing tables.

A listed manual shutoff valve is installed ahead of each appliance, with a sediment trap (dirt leg) downstream of the shutoff.

Flexible appliance connectors are limited to 6 feet, may not be concealed, and only one connector may serve each appliance.

Support intervals for horizontal steel gas piping: 1/2 inch at 6 feet, 3/4 inch and 1 inch at 8 feet, larger sizes at 10 feet.

Gas piping is prohibited in return-air plenums and elevator shafts; concealed runs avoid unions, and piping through masonry or concrete is sleeved.

Gas-fired appliances with an ignition source in a garage must have the ignition source at least 18 inches above the floor unless listed as flammable-vapor ignition resistant.

The system is pressure-tested with air or inert gas, gauge visible to the inspector, before gas is turned on; leaks are found with soap solution, never a flame.

Call 811 before any excavation; Oklahoma One-Call marks buried utilities, and lines near the marks must be exposed by hand digging.

Excavations 5 feet deep or more require a protective system (slope, bench, or shore) plus a ladder or ramp within 25 feet of lateral travel.

Before entering a confined space, test for oxygen, flammable gas, carbon monoxide, and hydrogen sulfide; ventilate and use an attendant.

Hot work such as soldering or brazing requires a fire watch during the work and at least 30 minutes afterward, with an extinguisher on hand.

PPE for plumbing work includes eye protection, gloves, hearing protection, and respiratory protection when cutting cast iron or using solvents and fluxes.

Gas piping and water piping must never be used as an electrical ground; use GFCI-protected cords on wet job sites.

Fall protection is required when working 6 feet or more above a lower level in construction.

Relief valve discharge piping must not be capped, trapped, or reduced in size, and must terminate where discharge cannot injure anyone or cause damage.