Perhaps a common image in people’s minds during the hot days of summer is a flowing fire hydrant in the street with children running through the cool water. It might be a common image, but it’s not usually a common occurrence. More likely, fire hydrants are opened to perform a fire hydrant flow test, which ensure the hydrant is functioning properly. Not all of these tests are performed the same way, depending on the city’s equipment and preferred techniques, but there are some basic practices that make up a standard hydrant flow test.
The first step to preparing for a test is to determine the type of hydrant. There are two types of hydrant: wet barrel and dry barrel, which indicates whether or not the hydrant is directly connected to the water source. In a wet barrel it is and there is always water in the hydrant, but in a dry barrel the water source has to opened to fill the hydrant. The organization performing the test should also notify the local water company before performing a test, because the flow from the hydrant could causes changes in water usage for nearby residents or businesses.
First, a person will have to locate which hydrant to test using a variety of considerations. Then, they will remove the pressure cap and attach their pressure gauge to the hydrant so they can see what the water pressure is when they start the flow. After the gauge is properly affixed, they can turn on the water and get a reading on the pressure. Once this is done they can record their readings and secure the hydrant once again by cutting off the water flow, returning the pressure cap, and ensuring all of the valves are turned off so the hydrant will not leak.