What types of joints are covered for cast iron pipes?

The code covers spigot and socket joints (run-lead joints and push-on rubber ring joints) as well as flanged joints.

How should the trench bed be prepared before lowering pipes?

The trench bottom must be evenly graded. Socket holes should be excavated at joint locations so the pipe rests continuously on its barrel, preventing point loads.

What is the procedure for hydraulic testing?

Pipes are filled with water slowly, air is fully expelled, and then the specified hydrostatic test pressure is applied using a pump and maintained to check for leaks.

IS 3114

: 1994

Code of practice for laying cast iron pipes

CurrentSpecializedCode of PracticeWater Resources · Public Health Engineering

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This code of practice outlines the procedures for laying cast iron pipes used in water supply and drainage systems. It covers site preparation, excavation, pipe laying, jointing methods (including lead and rubber ring joints), hydrostatic testing, and trench backfilling.

Code of practice for laying cast iron pipes

Quick Reference Values

minimum trench widthExternal diameter of pipe + 300 mm

minimum clearance pipe to trench wall150 mm

hydraulic test durationMaintain pressure for at least 1 hour

lead joint caulking clearanceMinimum 6 mm

Practical Notes

Ensure all air is expelled from the pipeline through air valves or highest points before applying hydrostatic test pressure to avoid false readings or bursts.

Provide concrete thrust/anchor blocks at all bends, tees, and dead ends to counteract hydraulic thrust forces.

Lead jointing requires skilled personnel and strict safety precautions to prevent moisture entrapment which can cause molten lead to splatter.

Cast iron pipes are largely being replaced by Ductile Iron (DI) pipes (IS 12288) in modern applications, but this code is essential for legacy systems.