Cast Iron Manhole Cover: Differences Between 700×800 and 700×900

The core difference between 700×800 and 700×900 cast iron manhole covers lies in their matching well opening sizes. The 700×800 model fits well rings with an inner diameter of 700 mm and an outer diameter of 800 mm, suitable for standard rainwater and sewage wells. The 700×900 model is designed for well rings with an inner diameter of 700 mm and an outer diameter of 900 mm, ideal for locations requiring larger installation space or special reinforcement.

1. Differences in Size & Structure

700×800

Inner diameter: 700 mm, Outer diameter: 800 mm. The thickness is generally 60 mm for standard type and 800 mm for reinforced type.

700×900

It shares the same inner diameter of 700 mm, while the outer diameter is extended to 900 mm. It features a larger installation frame and wider load-bearing support surface.

2. Application Scenarios

700×800

Widely used for rainwater and sewage wells on municipal roads and residential communities. It meets the heavy-duty load standard (Class D400) with a load capacity up to 40 tons.

700×900

Applicable to deep well openings, areas with anti-settlement requirements such as busy arterial roads, and special projects needing extra reinforcement like chemical parks. The enlarged outer diameter helps disperse pressure and improve overall stability.

3. Selection Guide

Choose 700×800 for standard well openings and conventional load requirements (≤ 40 tons). It is cost-effective and highly versatile.

Opt for 700×900 for deep well bodies, high-load areas such as expressways, or projects with anti-settlement demands for enhanced safety.