Journeyman Plumber ExamDrainage, Waste, and Venting (DWV) SystemsMedium
A plumber is designing a DWV system for a new medical laboratory. The lab will generate corrosive chemical waste from several sinks. Which of the following pipe materials is most suitable for handling this type of waste?
- ACopper drainage tube (Type DWV)
- BCast iron soil pipe (CISPI)
- CPolyvinyl chloride (PVC)
- DAcid-resistant high-silicon cast iron
Show answer & explanationAnswer & explanation
Correct answer: D. Acid-resistant high-silicon cast iron
Corrosive chemical waste requires specialized piping materials that can withstand chemical attack. Acid-resistant high-silicon cast iron is specifically designed for such applications due to its superior resistance to a wide range of acids and other chemicals.
Why the other options are wrong
- A. Copper is highly susceptible to corrosion from many common laboratory chemicals and is unsuitable for chemical waste.
- B. Standard cast iron is not sufficiently resistant to highly corrosive chemicals and would degrade over time.
- C. While PVC has some chemical resistance, it may not be suitable for all types and concentrations of corrosive laboratory waste, especially solvents or strong acids/bases.
Chemical Waste Piping Materials
Specialized pipe materials designed to safely convey corrosive, high-temperature, or otherwise hazardous chemical discharges from laboratories or industrial processes.
- Resistance to acids, alkalis, and solvents is paramount.
- Common materials include high-silicon cast iron, polypropylene (PP), and glass.
- Material selection depends on the specific chemicals and concentrations involved.
- Requires careful consideration of jointing methods and thermal expansion.
Memory trick: For 'ACID'ic waste, use 'SILICON' steel, a 'STRONG' pipe that's built to feel!