How are the Grease Interceptors referenced in
the Florida Code different than Concrete Grease Interceptors?
The Grease Interceptors that are referenced in the Florida Code (interceptors that meet ASME A112.14.3 or PDI-G101) are different than concrete grease interceptors. Concrete grease interceptors have been around virtually unchanged since Nathaniel Whiting obtained the first patent for one in the late 1800's. They work on the simple principle that FOG's (fats, oils, and greases) are lighter than water. And that given enough time, the FOG's will float to the top of a tank of water. Concrete grease interceptors are known as "Gravity Style" grease interceptors.
The type of Grease Interceptors that are referenced in the Florida Code (those meeting the requirements of ASME A112.14.3 or PDI G101) are not gravity style Grease Interceptors. They are Hydro-Mechanical Grease Interceptors. Hydro-Mechanical Grease Interceptors have been around for many years, and are commonly found under three compartment sinks, in kitchen areas. They work more efficiently than concrete interceptors by fine tuning the incoming influent stream. The incoming greasy water is directed through an inlet diffuser that slows down the waste stream, and diffuses it into the interceptor without disturbing the existing grease and solids layers.
Hydro-Mechanical Grease Interceptors are proven to separate grease more efficiently than concrete grease interceptors. Concrete grease interceptors typically operate in the 75%-80% efficiency range (according to the WERF Report, widely acknowledged as the most comprehensive grease trap study ever conducted. See link below). In order to meet the required standard, Hydro-Mechanical grease interceptors must remove a minimum of 90% of the incoming FOG's. The performance of the product must also be verified by independent testing.
Nearly ten years ago, several manufacturers introduced larger outdoor Hydro-Mechanical grease interceptors. These offer the significant advantage of separating grease more efficiently, in a much smaller footprint. They offer grease storage capacities equivalent to outdoor concrete interceptors, and are a lifetime design.