GI Pipe

In a Lightning Protection System (LPS), Galvanized Iron (GI) pipes are frequently used as protective conduits for down conductors or as part of the earthing/grounding assembly. Using a 1.5-inch diameter pipe provides significant structural durability and electrical continuity.

Key Applications in LPS

• Mechanical Protection: Used as a guard pipe for down conductors (like copper strips or aluminum cables) to protect them from physical damage and theft at ground level (typically covering the first 2.5 to 3 meters from the base).

• Earth Electrodes: Often utilized in pipe earthing systems where the GI pipe serves as the primary electrode driven into the soil.

• Support Masts: Acts as a sturdy mounting pole for air terminals (lightning rods) on rooftops.

Technical Specifications & Standards

To ensure compliance with standards like IEC 62305 or BNBC, the following specifications are generally required:

Installation Best Practices

1. Hot-Dip Galvanization: Ensure the pipe is hot-dip galvanized rather than electro-galvanized. Hot dip provides a much thicker zinc coating essential for the 20+ year lifespan required for LPS components.

2. Continuity: If the pipe is being used as a functional part of the earthing system, all joints should be threaded and treated with anti-corrosive conductive paste or welded and then painted with zinc-rich cold galvanizing spray.

3. Perforation (for Earthing): If used as an earth electrode, the lower section of the pipe is often tapered and perforated (drilled with small holes) to allow moisture and salt/charcoal treatment to maintain low soil resistivity.

4. Bending: Avoid sharp bends that could stress the galvanization layer, as micro-cracks can lead to premature rusting.

Why 1.5" Dia?

While 1" or 1.25" pipes are sometimes used, the 1.5" diameter is preferred for industrial applications because it offers a higher surface area for current dissipation in the soil and greater "wind load" resistance when used as a mast for air terminals.