Carson Brooks Jumbo Valve Box Extension

The Carson Brooks 1220 Jumbo extension adds approximately 152 mm (6-inch) of depth to a compatible 1220 enclosure when pipework, manifolds or valves need more vertical clearance. It increases working space without changing the surface opening.

Key details

• Extension section for the Carson Specification Grade 1220 family only
• Nominal 305 × 508 mm (12 × 20-inch) format
• Nominal added depth: 152 mm (6-inch)
• HDPE construction with a flared profile
• For light-duty pedestrian or greenbelt installations as part of a compatible body-and-cover assembly

This is the extension only; the main body, cover and internal equipment are not included unless expressly stated. Confirm that the existing enclosure is model 1220 and plan the final depth before excavation. Support the complete assembly evenly and do not use it to make a traffic-rated chamber.

Matching parts: 1220 Jumbo valve box and standard 1220 lid.

Manufacturer information: Carson 1220 product page and official 1220 body, cover and extension sheet (PDF).