By Mark Gimson
Municipalities that are looking to accurately measure their water flow rates often fall into one of three categories:
- They want a flow control valve that has the ability to vary flow rates over time but would rather not to have to install a flowmeter, a valve with an actuator and positioner.
- When filling a reservoir they would like to know how many gallons have been used.
- They would like to install a conventional flowmeter in their control valve station but don’t have the space.
The common choice in the municipal world to date has been the electcro-magnetic flowmeter due to cost, reliability, turndown etc. Unfortunately they require straight runs upstream and downstream prior to the meter – typically 5 pipe diameters upstream and 2 diameters downstream to give reasonable accuracy. There are other technologies but they also require straight runs and in many cases even more than the magnetic flowmeter.