227 environmental
71 Narrow Lane Leicester
Tel 01162830064
Fax 05601163691
2012
Friday, 23 March 2012
WTW Flow meters Feasibility – Severn
Trent Water
Water Treatment Works Flow meters Feasibility project for Severn
Trent Water - Frankley Mythe and Mitcheldean Central UK
Project Details
Client
Severn Trent
Location
Midlands and South West UK
Type of Contract
Feasibility and outline Design. Project Value £0.6 million
Problem
The existing water treatment works water into supply meter
were out dated, incorrectly sized and incorrectly located. The
meters were known to me inaccurate. 227 was asked to carry
out a feasibility study by the client following extensive
successful work on other large diameter meters projects.
Pipeline diameters at Frankley 43" x 2No 42" and 60"
Pipeline diameters at Mythe 30"
Pipeline diameter at Mitcheldean 800mm
Benefits
The projects were scoped out and the key inputs identified, this
enabled the design team to carry out full design and project
implementation without uncertainty as to the viability of the project.
Outcome
Completed on time, in budget with minimal / managed impact
on water company customers and other stakeholders.
WTW Large diameter meters Midlands and South West UK
07 February 2016 P a g e | 1
227 Environmental were asked to provide engineering services which included feasibility and
outline design for seven source and strategic meters measuring the distribution input from
Frankley, Mythe and Mitcheldean WTW. The brief was to establish how the new meters could
be installed without disrupting the downstream wider distribution areas. This for Frankley was
the whole of Birmingham, for Mythe Cheltenham and Part of Gloucester and Mitcheldean the
Gloucester area. The meters needed to be correctly sized in order to measure the flow with an
accuracy of 0.20% or better. The pipeline insertion system and chamber designs required
outline specification, feasibility works also included the installation of verification points and
connection to local eSCADA systems. The meter pipe work needed to be reduced in diameter in
order to ensure the velocity envelope across the full flow range was captured within the most
accurate band for each flow meter. This required careful model and design to ensure the
pressure reductions created by the meters and pipe work did not have an adverse effect on
downstream distribution pressures. In the case of Mitcheldean and Frankley the existing
chambers where measured and incorporated into the design with minor modifications to
reduce costs. Each site also had particular flow dynamics issue due to the proximity of pumps
and bends in the pipe work. To counter the swirl issues in the mains 227 worked with a
company in the US to specify flow conditioning systems to be installed in the lead in pipe work
and also specified the optimum location within the delivery maims in order to attenuate and
condition the flow. The project was completed following extensive hydraulic modelling, this
identified the exact time and duration for the meter insertions, network valving /
reconfiguration and downstream impact modelling. The outcomes were full feasibility study
and outline design / design brief. The project duration was 6 months and was successfully
completed.
WTW Large diameter meters Midlands and South West UK
07 February 2016 P a g e | 2