Pipe materials – common joint for asbestos-cement (AC) pressure pipes Which joint is most commonly used to join asbestos-cement (AC) water pipes in distribution systems?

Introduction / Context:Selection of a pipe joint depends on pipe material and the need to accommodate misalignment, expansion, and field assembly speed. Asbestos-cement (AC) pipes historically used mechanical couplings suited to their material characteristics.

Given Data / Assumptions:

• Legacy AC pressure mains in water distribution (now often replaced by DI/HDPE).
• Field assembly with minimal hot-works.

Concept / Approach:Mechanical couplings such as dresser couplings provide a flexible, gasketed connection between plain-ended pipes. They suit AC pipes because they avoid excessive localized stresses and allow small angular deflections. Flanged joints are more typical with metallic pipes and appurtenances; lead-caulked spigot-and-socket joints are associated with cast iron; simplex-specific joints are uncommon in AC practice.

Step-by-Step Solution:Match pipe material (AC) with a widely used mechanical joint → dresser coupling.Exclude flanged and lead-caulked options as less common for AC distribution lines.Select “Dresser coupling joint.”

Verification / Alternative check:Older design manuals and vendors list dresser-type couplings and AC collars as typical for AC pipes, offering ease of repair and insertion.

Why Other Options Are Wrong:

• (a) Flanged joints used mainly at valves/equipment, not long runs of AC pipe.
• (b) Gland-type flexible joints are more typical for DI/steel.
• (e) Lead-caulked spigot-socket is a cast-iron tradition.

Common Pitfalls:Applying high bolt torque or misalignment on brittle AC pipes; always follow torque and insertion limits of the coupling manufacturer.

Final Answer:Dresser coupling joint