PC Material Selection & Properties 3 — Questions and Answers
Question 1: What is the maximum temperature rating for standard CPVC pipe used in residential hot water distribution?
- 140°F (60°C)
- 180°F (82°C) (Correct answer)
- 212°F (100°C)
- 100°F (38°C)
Correct answer: 180°F (82°C)
CPVC pipe is rated for continuous service up to 180°F (82°C), making it suitable for hot water supply systems.
Question 2: Which cast iron pipe joint system uses a rubber gasket compressed by a stainless steel clamp?
- Hub-and-spigot lead joint
- No-hub (neoprene gasket) coupling (Correct answer)
- Flanged joint
- Bell-and-socket joint
Correct answer: No-hub (neoprene gasket) coupling
No-hub cast iron pipe uses a neoprene gasket and stainless steel clamp assembly, providing a flexible, leak-proof joint without molten lead.
Question 3: Which property of polypropylene (PP) pipe makes it preferred for chemical drain waste applications?
- High flexibility
- Excellent chemical resistance to acids and bases (Correct answer)
- Low cost compared to PVC
- High pressure rating
Correct answer: Excellent chemical resistance to acids and bases
Polypropylene has excellent resistance to a wide range of acids, bases, and solvents, making it ideal for laboratory and chemical waste drainage.
Question 4: What is the purpose of the 'K' designation in Type K copper tubing?
- It indicates the tubing is suitable for gas service
- It denotes the thickest wall of the copper types for highest-pressure applications (Correct answer)
- It is color-coded for cold water only
- It indicates the tubing is pre-insulated
Correct answer: It denotes the thickest wall of the copper types for highest-pressure applications
Type K has the thickest wall of the three copper types, making it suitable for underground service and higher-pressure applications.
Question 5: A plumber needs to install drain piping in an area exposed to petroleum solvents. Which material is MOST appropriate?
- ABS
- PVC Schedule 40
- Cast iron (Correct answer)
- CPVC
Correct answer: Cast iron
Cast iron is inert to petroleum solvents and provides the best chemical resistance for drain systems exposed to hydrocarbons.
Question 6: Which solder alloy is required by the Safe Drinking Water Act for joints in potable water piping?
- 50/50 tin-lead solder
- Lead-free solder with no more than 0.2% lead (Correct answer)
- 60/40 tin-lead solder
- Silver-bearing solder with 2% lead
Correct answer: Lead-free solder with no more than 0.2% lead
The Safe Drinking Water Act mandates lead-free solder (maximum 0.2% lead by weight) for all potable water copper joints.
Question 7: What characteristic makes brass fittings suitable for use with both copper and CPVC piping systems?
- Brass is cheaper than plastic fittings
- Brass is compatible with solvent cement
- Brass is NSF-listed, corrosion-resistant, and can use threaded or sweat connections (Correct answer)
- Brass expands at the same rate as plastic
Correct answer: Brass is NSF-listed, corrosion-resistant, and can use threaded or sweat connections
Brass fittings are NSF-listed for potable water, resist corrosion, and are available with threaded or solder-end connections compatible with multiple piping materials.
PC Material Selection & Properties 3
What is the maximum temperature rating for standard CPVC pipe used in residential hot water distribution?