There are many options for ensuring accurate billing of water used at established industrial customer locations. But how do municipalities or businesses keep track of water availability and use for intermittent applications or movable access points? We spoke with McCrometer, Inc.’s Marc Bennett for insight into how water utilities and industries can efficiently track and allocate water use for billing or internal accounting purposes in such ad hoc applications.

How are fire hydrant meters typically used?

Fire hydrant meters are typically used to document flow capacity at a specific point in a distribution system or to track a cumulative volume of water use over a period of time. These meters are generally employed for temporary installations or testing in applications where a fire hydrant is the targeted source of water, but they can also be installed in other application environments as needed.

What advantages do fire hydrant flow meters deliver in those applications that other types of meters do not?

Because they come with a standard-size threaded connector for fire hydrants, attachment is quick and easy, so there is no need to customize another style of meter to fit a hydrant application. Although many fire hydrant flow meter applications are for temporary uses, they can also be permanently installed into an application.

What are the most common applications for fire hydrant flow meters?

Testing companies, fire departments, and other municipal entities typically conduct flow tests to determine that each fire hydrant can deliver a minimum rate of flow (gpm) — usually at 20 psi residual pressure — for a duration of 2 hours. Those tests are based on the hose length used. Fire hydrants that do not have sufficient capacity receive no credit for insurance-rating purposes, although they may be used for limited fire-suppression capability.

How are fire hydrant flow meters used for other industrial applications?

In addition to using fire hydrant flow meters for their own flow testing, municipalities can employ them to document water-use charges to specific cost centers for uncommon applications — such as filling community swimming pools or summer hydrant openings during heat waves.

Municipalities might also lease or lend meters out to construction contractors who have received permits for a volume of water to be used for temporary projects. For example, businesses that receive permits to use hydrant water for tasks such as power washing, street cleaning, or other general construction, dust suppression, or irrigation uses, are typically required to report the amount of water used.

Also, private businesses can take advantage of fire hydrant flow meters to track internal water usage in temporary or on-again/off-again applications downstream from their water-utility meter. Doing so makes it easy to provide a separate cost accounting of the volume of water associated with such special applications. The meter design is suitable for any potable or non-potable water application, but not for wastewater use.

Special industry application uses not related to treated water flowing from a water utility could include withdrawals from surface water or groundwater sources for natural gas fracking applications. Even when not connected to a traditional hydrant fixture, these easy-to-install meters can make it easier to document the exact volume of water used under permitted allocations, instead of relying upon rough estimations based on tanker truck sizes.

What are some key features to look for when specifying a fire hydrant flow meter for an industrial or commercial application?

While fire hydrant flow meters are typically not permanently installed, it does pay to consider features that will provide maximum accuracy and reliability for long-term performance. Consider these features that deliver convenient, reliable operation in use to document volume measurements or pressure performance requirements:

• Meter Size. Make sure that the chosen fire hydrant flow meter will be able to handle the anticipated maximum flow requirement for the application. For example, at a minimum 20-psi pipeline pressure, a full 4”-diameter flow meter tube will be able to sustain 2.5 times greater flow volume than a 2.5” tube.
• Accuracy. Compare how accuracy and repeatability remain consistent at both full flow and low flow. Meter features such as straightening vanes will limit potential turbulence that might otherwise affect reading accuracy.
• Flow Measurement. Combined capabilities for both instantaneous flow rate and for total flow — in a range of different units of measure (e.g., gallons, cubic feet, etc.) — make it easier to document test conditions and total consumption, regardless of the application.
• Mounting. Fire hydrant flow meters that can be configured for vertical or horizontal mounting provide flexibility and accuracy to accommodate any use or setting.
• Construction. Features such as stainless-steel construction, built-in check valves, and strainers will deliver long-term reliable performance, even with untreated water such as surface water that might contain some suspended solids. Modular assemblies can provide for easy removal and maintenance of major components.