Water hammer is a common plumbing issue that can cause noisy and disruptive banging sounds in the pipes when water is turned on or off. It occurs when rapid changes in water flow cause pressure surges, resulting in the pipes shaking and vibrating. One possible cause of water hammer is a flawed expansion tank. In this article, we will explore what an expansion tank is, its function in a plumbing system, and how a flawed expansion tank can lead to water hammer.
Understanding Expansion Tanks
An expansion tank is an important component of a plumbing system that helps regulate water pressure. It is typically installed near the water heater or in the main line, and it consists of a container divided into two sections – one for water and another for air. The purpose of the air-filled section is to provide a cushion or buffer for the water, allowing it to expand and contract without causing pressure surges.
The Function of an Expansion Tank
Water expands when heated, which can increase the pressure in a closed system such as a plumbing system. The expansion tank acts as a safety valve, accommodating the increased volume of water when it expands without causing pressure spikes. When a plumbing fixture is in use, the water flows into the expansion tank, compressing the air inside. As the water volume expands, the pressure inside the tank increases, and when the fixture is turned off, this stored pressure helps push the water back into the plumbing system. This cycle helps maintain consistent water pressure and prevents pressure surges that can lead to water hammer.
The Effects of a Flawed Expansion Tank
A flawed or malfunctioning expansion tank can disrupt the delicate balance of water pressure in a plumbing system, potentially resulting in water hammer. Here are some common issues that can occur:
- Air Cushion Loss: Over time, the air inside the expansion tank may become absorbed into the water, reducing its ability to provide the necessary cushioning effect. This can lead to increased pressure in the plumbing system, causing water hammer.
- Waterlogged Tank: If the diaphragm that separates the air and water sections of the expansion tank fails, water can permeate the air chamber, effectively waterlogging the tank. A waterlogged tank no longer has the ability to absorb water expansion properly, leading to pressure surges and the likelihood of water hammer.
- Improper Sizing: Expansion tanks come in a variety of sizes, and it is crucial to select the right size for the specific plumbing system. If an expansion tank is undersized, it will not be able to accommodate the water volume expansion adequately, potentially resulting in pressure surges and water hammer. Conversely, an oversized expansion tank may not allow for enough compression of the air, leading to similar issues.
- Incorrect Installation: Improper installation of an expansion tank can also lead to problems. If the tank is not positioned correctly or the plumbing connections are not secure, it may not function as intended, causing pressure irregularities and potential water hammer.
While water hammer can have several different causes, the condition of the expansion tank in a plumbing system should be considered. A flawed expansion tank can disrupt the delicate balance of water pressure and lead to the disruptive and potentially damaging effects of water hammer. Regular maintenance, including checking the air cushion, inspecting for waterlogging, ensuring proper sizing, and correct installation can help prevent issues with expansion tanks and mitigate the risk of water hammer in a plumbing system.