CSLB C-36 Plumbing ContractorPlanning and EstimatingHard
A plumbing contractor is reviewing a blueprint for a new medical laboratory specializing in chemical research. The plans indicate the installation of a specialized drainage system for chemical waste. Which material is generally NOT acceptable for chemical waste drainage piping due to its susceptibility to corrosion or degradation by common laboratory chemicals?
- AType M copper
- BHigh-density polyethylene (HDPE)
- CBorosilicate glass
- DPolypropylene (PP)
Show answer & explanationAnswer & explanation
Correct answer: A. Type M copper
While Type M copper is suitable for many standard plumbing applications, it is highly susceptible to corrosion and degradation from a wide range of laboratory chemicals, particularly acids and strong bases. Specialized plastic materials like PP and HDPE, or borosilicate glass, are designed to withstand such corrosive environments.
Why the other options are wrong
- B. High-density polyethylene (HDPE) offers good chemical resistance and is suitable for many chemical waste applications.
- C. Borosilicate glass is highly resistant to chemical attack and is frequently used for laboratory drains.
- D. Polypropylene (PP) is commonly used for chemical waste due to its excellent chemical resistance.
Chemical Waste Drainage Piping
Specialized piping systems designed to safely convey corrosive, hazardous, or high-temperature chemical wastes from laboratories or industrial processes to treatment or disposal facilities.
- Requires materials resistant to a wide range of chemicals.
- Selection depends on the specific chemicals being drained.
- Common materials include PP, HDPE, PVDF, and borosilicate glass.
Memory trick: For labs, copper's a 'no-go', plastics and glass are the way to flow.