Carson Brooks Jumbo Valve Box

The Carson Brooks 1220 Jumbo Valve Box forms a large, accessible underground chamber around irrigation valves, manifolds, filters and cable connections. It keeps soil away from serviceable components while retaining ground-level access for isolation, inspection and repair.

Dimensions and construction

• Model: Carson Specification Grade 1220; nominal 305 × 508 mm (12 × 20-inch) format
• Nominal body depth: 305 mm (12-inch)
• Manufacturer drawing: approximately 311 × 464 mm clear top opening, 384 × 543 mm outside at the top and 505 × 667 mm across the flared base
• HDPE body with rigid, flared sidewalls and two or three pipe-entry positions, depending on configuration
• For light-duty pedestrian or greenbelt locations only; not for vehicle-loading areas

Selection and installation

Check the full footprint as well as the clear opening: the flared base is substantially larger than the nominal 12 × 20-inch cover format. Allow space to operate and remove valves, service filters and make cable joints. Support the enclosure on stable, compacted material, make only the pipe openings required and finish the cover level with the surrounding surface. It is an access chamber, not a watertight tank or structural manhole.

Matching parts: standard 1220 lid, 1220 extension and artificial-grass 1220 cover.

Manufacturer information: Carson 1220 product page and official 1220 dimension and specification drawing (PDF).