Abstract: A vessel designed to separate out clean water from produced oil is disclosed. Conventional free water knockout vessels (FWKO) are normally disposed horizontally, and have a large diameter. The large diameter maximizes the distances between the oil/water interface and the exit points on the vessel for the water and the emulsion. The larger the vertical distance from the oil/water interface, the greater the chance that the oil and water can be agitated by slugs of gas and fluids. Tilting the vessel and reducing the diameter minimizes the distance the fluid has to travel to reach the top and bottom walls of the vessel, maximizes the distances from the oil/water interface, utilizes more fluid space in the vessel, reduces agitation caused by gas slugs, and forces the water to travel a longer distance which provides more separation time. Emulsions in most pipelines stratify, and the inlet nozzle is designed in such a way that it encourages the stratification of oil and water to continue as it flows into the vessel.