What is water hammer? How can it be prevented?
High-temperature steam is used in the engine compartment for various purposes, such as heating fuel lines and tanks. Water hammer is a common phenomenon caused by water accumulation in steam lines. Let’s understand how water hammer occurs and how to prevent it.
How does water hammer occur?
When a steam line is closed after use, water accumulates inside the line. This is primarily due to condensation of the accumulated steam. When high-temperature steam flows through a water-filled line, it comes into contact with the water and causes it to sink.
When steam comes into contact with water, it condenses, creating a vacuum that forces water toward the open valve at high speed. The water then impacts the valve at high speed, causing damage or even complete rupture. In the past, valve ruptures caused by water hammer have led to catastrophic accidents, even resulting in fatalities. Therefore, it is crucial to take every possible measure to mitigate the effects of water hammer.
How can water hammer be prevented?
The most important way to prevent water hammer is to drain the water before it flows through the steam line again. Water is drained from the steam line through the drain fitting.
The water must be completely drained to clean the pipes. Then, the steam valve must be slightly opened to allow the pipes to warm to operating temperature. This also ensures that any condensate generated when steam enters the pipes through the open valve is removed. The drain outlet must be checked regularly to ensure complete drainage.
Steam Drainage
Avoid sharp bends in the steam pipes, as these can increase condensate.
Once the water has completely drained and the drain sound has changed to steam, the steam valve must be reopened. This process must be done slowly and gradually.
After a period of time, the drain valve must be completely closed and the steam valve fully opened. This method prevents water from accumulating in the pipes, ultimately eliminating water hammer.
