Updated: Mar 7, 2020
A fuel water separator is a device that works to ensure clean fuel is delivered to the engine. Properly speaking, a fuel water separator is a small filtering device used to remove the water from the diesel fuel before it reaches to the sensitive parts of the engine. Water and contaminants have a direct impact on the service life and performance of diesel engines.
Besides being abrasive to engine components and cylinder walls, water and contamination displaces diesel fuel’s lubricative coating on the high precision injector components, causing tolerance erosion, surface pitting, fuel pressure loss and poor performance. Unfortunately, there is no way to completely prevent water from contaminating fuel. Condensation is constantly forming inside fuel tanks.
Nowadays, there are number of manufacturers who make fuel water separators with their concept of operation being common and only design variations being the major difference. The first stage of the fuel water separator uses a pleated paper element to change water particles into large enough droplets that will fall by gravity to a water sump at the bottom of the filter. The second stage is made of silicone-treated nylon that acts as a safety device to prevent small particles of water that avoid the first stage from passing into the engine.
To remove the water from the fuel water separator the operator should periodically check the fuel water separator and open the valve to drain the water.
However, on small gensets one fuel water separator unit could be used while on big gensets up to three or more could be used.
If the separator fails, any water in the fuel can wear away lubricants on the diesel fuel injectors. When the device removes contaminants and solid materials, it helps prevent engine clogging. It can be seen that fuel water separator is a important part of fuel system.