What is the purpose of having two vents at differing heights in an oil interceptor?

The primary purpose of having two vents at differing heights in an oil interceptor is to maintain proper air circulation within the unit, thereby preventing the accumulation of explosive gases. Oil interceptors are designed to separate oil and other hydrocarbons from wastewater before it enters the drainage system. As these materials rise to the surface of the water, they can create a buildup of gases that could potentially lead to hazardous conditions.

By having vents placed at different heights, the system can effectively release these gases while allowing for fresh air to circulate, which helps to mitigate any risk of an explosive atmosphere. One vent, usually situated higher, allows for the escape of lighter gases, while the lower vent provides a pathway for air to enter the interceptor, promoting continuous air movement.

The other potential purposes listed do not effectively address the primary concern of gas management within the interceptor. Rainwater drainage, while important in other contexts, does not pertain directly to the function of individual vents in oil interceptors. Monitoring oil levels is generally done through different mechanisms rather than relying solely on venting methods. Lastly, while easier cleaning could be a secondary benefit, it is not the primary purpose of having dual vents at varied heights.