450mm Inspection Chamber Restrictor Ring

This underground inspection chamber restrictor ring (sometimes known as a reducer ring) is designed to reduce/restrict the access on 450mm inspection chambers (including B5494 & B5696) from 450mm diameter to 350mm diameter. This reducing ring is easy to install and can be installed for any 450mm chamber base regardless of the depth/invert, however commonly used where the chamber depth/invert is greater than 1 metre (1000mm).

With your restrictor ring and chamber components, typically you would require a cover/lid. You can browse through our manhole covers & frames to find a cover lid to suit your requirements.

Manufactured in the UK by Brett Martin also provides the installer with a reliable product that will continue to perform. Combining ease of installation with maximum performance, the chamber assemblies meet requirements of Building Regulations Part H1.

We would recommend this product and the rest of the Underground Drainage range to be installed with Lubricant to help with pipe jointing any rubber seal connections in PVC, clay and concrete.