According to the site Verisk, there were approximately 7.5 million fire hydrants in the United States as of 2015. All of these hydrants require the proper flow of water to be of proper use to fire departments. Without the proper flow, the pressure needed to deliver water could be minimized and result in further fire damage to a structure. This is why utilities and emergencies services organizations across the country perform a hydrant flow test regularly on the many units in their operation area.

According to the National Fire Protection Association’s recommended practice for fire flow testing, hydrants should have a residual pressure of 20 pounds per square inch (psi)  for effectiveness in fighting fires and prevention from contamination of the public water system from any backflow. The test is also done in order to design a commercial or residential fire sprinkler system. When the flow is below 20 psi, the sprinkler system may not deliver the proper amount of liquid to mitigate flames.

Testing of hydrants is done with equipment from companies such as Hurco Technologies. For those hydrants which can’t be accessed by a fire truck, a portable and rechargeable hydrant opener may be utilized to start the flow test. Once the hydrant is opened a hose is connected to it with the other end normally connected to a portable unit in order to record flow data and any errors. This data is stored and sent to a central unit in order to review issues across the area.

If a problem is discovered, the next step is to determine what needs to be done to fix the issue. In some cases, water utilities need to get involved in order to get under the hydrant to see if the problem is a damaged pipe or something else further down the supply. Another potential problem could be at the hydrant itself. At that point, the hydrant may be deactivated for a time as the necessary parts are ordered for the repair. When this is all done, another flow test is performed to ensure all of the issues have been resolved.

Should you have further questions on flow testing for hydrants, consult with your local fire department or water company to learn their best practices.