Three Chamber

Magnetic Meters

Problem

Magnetic flow meters are reliant on the pipe running full to provide accurate flow data.
An early solution was to relay the pipework with a ‘Swan Neck’ arrangement to generate full conditions and then bury the meter.

This solution led to problems with verification, entrained air and settlement clogging the pipes. There were even occasions where burying the meter disguised that the pipe was not running full.

Solution

The three chamber  system consists of;  a down chamber, which is sized to allow air to be released, a middle inspection chamber, where the meter is fitted and a clamp on meter can be installed, and up chamber where settlement takes place.

The system provides easy access for the inspection and verification and can be maintained by sucking out the settlement in the up chamber and jetting the pipework.

Outcome

This system is now the preferred method for installing Magnetic Meters in Severn Trent and has been used in their recent remedial programme. The system can be designed in standard sizes which has simplified costings and installation for the main contractor.