Detecting the presence of water in a storage tank is one of the most important jobs of any storage tank operator. Water can cause a number of problems in a storage tank and its related component. It can degrade the quality of fuel, affecting the performance of vehicles that use said fuel. It can contribute to bacteria growth that shortens the lifespan of tank components. And of course, it can contribute to corrosion, resulting in a fuel leak and environmental hazard.
In two of our recent blogs, we’ve talked about how water gets into a storage tank, as well as how to prevent water from entering a tank. In this week’s blog, we’ll talk about how to detect water in a storage tank.
How to Detect Water in a Storage Tank
Automatic Tank Gauges
Most storage tanks are installed with automatic tank gauges (ATGs), which are used to detect water in the tank. Monitor these gauges and look for readings that suggest the presence of water in the tank. It’s important to note that the sensors need to be maintained properly so they can function properly. Lack of maintenance can cause an ATG not to deliver the correct readings.
There are a number of manual tank gauging methods that can also be used. Many guidelines suggest these methods be used in conjunction with automatic gauges, and that the two readings be compared. Any discrepancy between the readings could suggest the presence of water in the tank. A common manual gauging method involves the use of alcohol-compatible water paste on the gauge stick.
Pulling product samples from the tank is a good way to get a visual of the contents of the tank. A fuels sample that looks hazy or waxy most likely has water in it. Further analysis of the sample can be conducted by using a field detection kit, which you can get from your petroleum equipment supplier. Here are a few guidelines from the STI that will ensure you get the best possible sample from the storage tank.
- “Pull samples from the low end of the tank – tanks are often installed with a slight tilt to allow for water to collect in the sump.”
- “Be aware of the pitfalls of using the fill tube as the sampling port – if it is not located at the low end of the tank, sludge or water may not be detected. Also, if the fill tube is not installed straight, water and sludge may not be detected or it may appear that there is less quantity than there really is.”
- “If possible, samples should be taken from more than one location in the tank.”
If you have any questions about what equipment may already be installed on your storage tank system, talk to your petroleum equipment contractor and fuel supplier. They can also provide additional guidance on operations and maintenance.