OH Journeyman Plumber flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Drainage fixture unit
- A unit of measure that expresses the probable waste discharge load of a fixture; it is used to size drainage and vent piping, not water supply piping.
- Trap seal depth
- The vertical distance between the trap weir and the top of the trap dip; the code minimum is 2 inches and the maximum is 4 inches.
- Air gap backflow protection
- A physical separation between a potable water outlet and the flood-level rim of a receptor; it must be at least twice the pipe diameter and never less than 1 inch.
- Flood-level rim
- The uppermost edge of a fixture over which water would overflow onto the floor; backflow devices and air gaps must be installed above this level.
- Reduced-pressure-zone assembly
- A testable backflow preventer with two check valves and a relief valve; it protects against both backsiphonage and backpressure and requires annual testing.
- Vacuum breaker
- A backflow device that admits air into a pipe to break a siphon; it protects against backsiphonage only and is not suitable where backpressure can occur.
- Water hammer arrestor
- A device installed near a quick-closing valve to absorb the pressure surge caused by sudden stoppage of water flow; it must remain accessible for service.
- Horizontal drain slope
- The fall per foot of horizontal drainage pipe; 1/4 inch per foot is required for pipe 2 1/2 inches and smaller, and 1/8 inch per foot for 3 inches and larger.
- Vent stack termination
- A vent must extend at least 6 inches above the roof and snow line and terminate at least 10 feet from operable windows or air intakes.
- Wet vent
- A single pipe that serves as both a drain for one fixture and a vent for another; it must be sized and arranged so the vented fixture's trap remains protected.
- Cleanout requirement
- An accessible opening in a drainage system for clearing stoppages; required at the base of stacks, at the end of horizontal runs, and at changes in direction greater than 45 degrees.
- Backwater valve
- A device installed on a drainage branch subject to sewer backflow; it closes automatically when flow reverses and must be installed so it can be serviced.
- Ohio Plumbing Code basis
- Ohio adopts the International Plumbing Code with state amendments; local jurisdictions may add amendments, and the authority having jurisdiction enforces the adopted edition.
- Rough-in inspection
- An inspection of piping and fittings performed after rough-in and before walls are closed; work must not be concealed until the inspector approves it.
- Journeyman plumber scope
- A licensed journeyman may perform plumbing work under a licensed plumbing contractor; apprentices work under direct supervision of a licensed plumber.
- Stop-work order
- An order issued by the authority having jurisdiction halting work that violates code or lacks a permit; work may not resume until the issue is corrected and approved.
- Soldering safety
- Before soldering, drain water from the pipe and open the system to atmosphere; trapped water or air prevents solder flow and can cause a dangerous blowout.
- Confined space entry
- Entry into a sewer manhole or pit requires atmospheric testing, ventilation, and a permit; test for oxygen, hydrogen sulfide, and combustible gas before entering.
- Tubing cutter use
- A tool that cuts copper tube square without leaving a burr; the inside of the tube must be reamed after cutting to prevent turbulence and erosion-corrosion.
- Copper tube types
- Type K is heaviest and used underground; Type L is medium; Type M is lightest and has restricted uses. Color coding is green, blue, and red respectively.
- PEX joining methods
- PEX is joined with crimp, clamp, or press fittings; each system is manufacturer-specific and must not be mixed, and PEX must be protected from UV light.
- Dielectric union
- A fitting that separates dissimilar metals such as copper and steel to prevent galvanic corrosion at the connection point in a piping system.
- Sanitary tee fitting
- A drainage fitting with a curved branch that directs flow in the direction of drainage; it is used for vertical-to-horizontal transitions, not horizontal-to-horizontal.
- No-hub coupling
- A cast iron soil pipe coupling with a neoprene sleeve and stainless steel bands; it must be tightened to the manufacturer's torque specification.
- Pipe volume formula
- Volume equals pi times radius squared times length; convert cubic inches to gallons by dividing by 231, since 1 gallon equals 231 cubic inches.
- Slope drop calculation
- Drop equals slope multiplied by run; a 3-inch pipe at 1/8 inch per foot over 20 feet drops 2.5 inches from start to end.
- Pressure and head
- One psi equals 2.31 feet of water column; a 20-foot column of water exerts about 8.7 psi of static pressure at its base.
- Fitting takeout
- The distance a pipe must be shortened so it seats fully inside a fitting; it is subtracted from the measured center-to-center length before cutting.
- Water service sizing
- Total water supply fixture units are converted to probable demand in gallons per minute; pipe size is then selected to keep velocity within about 5 to 8 feet per second.
- T&P relief valve discharge
- A water heater's temperature and pressure relief valve must discharge to a safe point through a pipe that is not trapped or reduced in size.
- Drainage system test
- A drainage system is tested with water or air before concealment; a water supply system is tested at working pressure plus 50 psi for at least 15 minutes.
- Thermal expansion allowance
- PEX and CPVC expand with temperature changes; long straight runs need expansion loops or offsets so fittings are not stressed by movement.