Report No FR0364



Mar 1993



The new manifold specification will enable all boundary box manufacturers to make the meter/manifold connection to a consistent design. This will eliminate the variability between connections and hence will eliminate one factor identified in contributing to the internal by-pass of the meter.

The recommendations made for the retention of the o-ring in meters will reduce the chance of accidental o-ring removal.


To investigate and assess a new manifold specification in combination with various common meter types, in order to determine the efficiency of the connection made.

To test the retention of the inner o-ring in water meters so that a minimum standard can be determined.


Following the recommendations given in the report "Assessment of leakage in meter/manifold combinations and development of a preferred connector - FR0264"(1) discussions took place with members of the water industry and manufacturers, to enable a standard meter/manifold connector design to be prepared. The aim of providing a standard design was to eliminate manifold variation from meter recording accuracy and to eliminate the possibilities of internal by-pass of the meter. This experiment was to investigate the success of the manifold design in conjunction with four common meter types.

The security of the inner o-ring in the meter base is of great concern to users. Previous tests have shown poor meter accuracy in cases where the 0-ring is absent or misaligned. The security of the o-ring in the meter design needs to be examined.


The manifolds, in every combination with the meters and at two flow rates, gave an acceptable reading accuracy and gave no indication of any leakage at the meter/manifold connection or any meter by-pass.

Investigation of the inner 0-ring retention of the four supplied meter types showed best performance by the Socam meter with the inner retaining lip and the new Sensus meter with the 'sealed' o-ring.

Copies of the report are available from FWR, price 15.00, less 20% to FWR Members.