How should a hydrant be closed to prevent surges?

Closing a hydrant slowly is the best practice to prevent surges in the water distribution system. When a hydrant is closed quickly, it can create a sudden increase in water pressure, which may lead to water hammer – a phenomenon where a shock wave is created in the pipeline due to the rapid change in flow. This can cause damage to pipes, fittings, and even the hydrant itself.

By closing the hydrant slowly, the flow of water is gradually reduced, minimizing the risk of pressure surges and subsequent water hammer. This controlled procedure allows the system to adjust to the changes in pressure, promoting safer operation and extending the lifespan of the infrastructure.

Other options, such as leaving the hydrant open or closing it at an angle, do not address the need for pressure management and may create additional risks or inefficiencies in the water distribution system.