Plumbing Honor

Vocational Activities

Requirements

1. Make a diagram showing the piping system of a 4-room house, including water outlets for the kitchen, bathroom, and service area.

   Answer: You draw the diagram with: the inlet from the street passing through the water meter and the main valve; the riser and the upper water tank; cold branches to the kitchen (sink, refrigerator), bathroom (sink, toilet, shower), and service area (washtub, machine); hot branches from the heater; and a separate sewage network with traps at each wet point. — The standard follows NBR 5626/2020 (building cold water installations) and NBR 8160/1999 (sanitary sewage); the minimum required pressure is 10 kPa at points of use; the separation between the rainwater and sanitary networks prevents backflow — a principle applied in Brazilian plumbing projects since the 1970s and still in force today.

2. Demonstrate how to repair two galvanized steel pipes correctly.

   Answer: You close the main valve and empty the pipe. For a small leak: sand the area, apply Teflon tape, and seal with epoxy putty. For a large leak: cut the damaged section with a saw, cut a new thread with a die, apply thread sealant, and install a galvanized coupling or union. Slowly turn the water back on, checking. — Galvanized steel is classic piping that still exists in old houses; a hand die (Ridgid 12-R) makes BSP threads to the Brazilian standard; epoxy putty of the Durepoxi type resists up to 6 bar; galvanized couplings follow NBR 6925; its use dates from colonial Brazil and still predominates in old buildings from the early 20th century, in force.

3. Demonstrate how to repair a PVC pipe and a copper pipe.

   Answer: PVC: close the shutoff valve, cut out the damaged section, sand the ends, apply plastic adhesive (PVC cement) to both surfaces, and join with a coupling or slip fitting; wait 30 minutes before turning the water on. Copper: close the shutoff valve, file the ends, apply soldering paste, fit the coupling, and solder with a torch using tin solder. — Tigre-brand PVC cement makes a chemical weld between the surfaces; soldering paste (flux) cleans the copper before soldering; low-melting-point tin solder (220°C) is the standard; both techniques follow the NBR 5648 (PVC) and NBR 13206 (copper) standards — used in modern Brazilian residential plumbing currently in effect.

4. Demonstrate the ability to repair a leaking sink faucet and to replace or repair the flush valve of the toilet.

   Answer: Faucet: close the shutoff valve, disassemble the stem assembly, replace the worn washer or internal seal, lubricate with neutral grease, and reassemble. Toilet: close the wall shutoff valve, empty the coupled tank, unscrew the old valve, install the new one with a rubber seal, adjust the float, and test the flush. — A worn washer is the most common cause of leaks (NBR 10281 standardizes faucets); flush valves of the Hydra or Deca type follow ABNT standard 14534; adjusting the float of the coupled tank saves up to 6 liters per flush — a principle applied in modern Brazilian sustainable construction currently in effect.

5. Describe the appropriate drainage system for the house in item 1 and explain where traps and venting are used and what their purpose is.

   Answer: Drainage: PVC sewer pipes (40-100 mm) collect the wastewater from the fixtures (sink, shower, toilet) with a minimum slope of 2%, leading to the inspection box and to the public network/septic tank. The trap (S, P, or bottle-shaped) sits below each fixture and retains water that prevents odor and gases from coming back. Ventilation: vertical pipes that release pressure. — NBR 8160/1999 standardizes sanitary sewage; a trap without water loses its seal and releases odor; the vent pipe prevents the suction that empties the trap (siphoning effect); the vent column reaches the roof at least 30 cm above the water of the reservoir, according to the current Brazilian technical standard for sanitary installations in effect today.

6. Know how the hot and cold water system of a house works by making a plumbing scheme and defining each type of piping used in each system.

   Answer: System: cold water comes from the water tank through PVC pipes (solvent-weld or threaded, brown). Hot water comes from the heater (boiler or tankless) through CPVC pipes (orange, withstands up to 95°C) or copper. Each wet point receives a cold branch + a hot branch. A mixer combines the two temperatures at the desired shower or sink. — Brown PVC withstands up to 40°C and a pressure of 7.5 bar; orange CPVC resists up to 95°C and 6 bar; class E copper pipe is an expensive but durable alternative; tankless gas heaters have a typical flow rate of 12-25 L/min — a system standardized by NBR 7198 for hot water and NBR 5626 for cold water, in effect in Brazil.

7. Make a diagram of water heating using solar energy and apply it at a camp of your club.

   Answer: Diagram: the solar collector (a black panel with copper pipes) captures heat; an insulated reservoir (boiler) above the collector stores hot water by convection (thermosiphon). Connections: cold water inlet at the bottom, hot outlet at the top. At camp: install an improvised collector with a coiled black hose exposed to the sun, connected to a jug. — Solar thermal systems follow NBR 15569; the typical yield is 60% of solar radiation — about 4 kWh/m²/day in Brazil; a 25 mm black hose coiled in a spiral reaches 60°C in 2 hours of full sun, a technique used by Scouts and Pathfinders in rural Brazilian campsites since the 1980s, still in use.