In acid-bearing sewer networks, which material is preferred?

• A. Polyethylene pipe
• B. Cast iron pipe
• C. Vitrified clay
• D. Concrete lined pipe

Answer: (A)

In acid-bearing sewer networks, you need a material that won’t corrode or be degraded by acids and related by-products. Polyethylene pipe (HDPE) fits that need because it’s highly resistant to a wide range of acids and to sulfuric acid formed in sewer conditions, and it won’t rust or corrode like metal pipes. Its non-porous interior and fusion-welded joints create a tight, leak-resistant line, which is crucial in aggressive wastewater. It’s also flexible, helping it withstand ground movement without cracking. Cast iron would corrode in acidic environments, concrete-lined pipe can suffer chemical attack on the cement lining, and vitrified clay, while acid-resistant, is brittle and less forgiving in installation and long-term service. So polyethylene is the best choice for acid-bearing sewers.