Grille Manholes
Grille Manholes for drain and sewer systems supplied with standard C250 (25 tonnes) load rating and optional heavy-duty D400 (40 tonnes) versions, designed for drainage, inspection, and personnel access applications.
Overview
All grille manhole covers are supplied with a standard load rating of C250 (25 tonnes), with heavy duty D400 (40 tonnes) versions available for higher traffic and load conditions.
Drain & Sewer System Applications (As Provided)
Within drain and sewer systems, grille manholes are used alongside other structures such as inspection chambers, intersection structures, storm water overflow works, infall works (street type drainage), outfall structures, and valve works.
Standards & Definitions (As Provided)
- EN 476: Manholes represent the largest share of sewer and drain system structures, with inspection chambers to EN 476 increasingly in use.
- EN 752-1: A manhole is defined as a chamber with a removable cover on a drain or sewer permitting personnel entry.
Technical Specifications
- Standard load rating: C250 (25 tonnes)
- Heavy-duty option: D400 (40 tonnes)
- Material: ductile iron or galvanized steel
- Available sizes: 300×300 mm to 900×900 mm (custom sizes on request)
Installation Guidelines
- Set in concrete surround to the appropriate load class
- Ensure level seating to prevent rocking under traffic
- Apply anti-corrosion treatment to frame bedding surfaces
