Overview
The Traditional grease interceptor line is the cornerstone product of the Pioneering concept. For more than fifty years, Jay R. Smith Mfg. Co.^® has conducted hundreds of tests, in the laboratory and in the field, in order to offer the most efficient Grease Interceptors with improved operational characteristics suitable for most applications. The Traditional Grease Interceptor is designed for practical applications. These interceptors bear the certification seal of the Plumbing and Drainage Institute (PDI). Rating, sizing and special features of these units can be found in the Smith Yellow Pages^® Catalog, 8000 Series Interceptors. The Traditional line may be installed either on-grade, semi-recessed or fully recessed in the floor. In addition, the fully recessed installations have the option of a partially or completely enclosed cradle to act as a drip pan.

When to Use the Traditional Unit
The Traditional Grease Interceptor is recommended for areas where the accumulation of grease, fat, oil or other similar line-clogging contaminants should be prevented from entering the drainage line. The Traditional Grease Interceptor should always be considered when designing the plumbing drainage system in any restaurant, cafeteria, hotel, school, hospital, institutional or commercial building as well as food processing plants, dairies and other industries having facilities for the preparation and serving of food in quantity. In these installations, where grease and fats are by-products, an efficient Smith interceptor should be installed to prevent this material from entering the drainage line.

Maintenance
All interceptors must be cleaned regularly. The frequency of grease removal is dependent upon the capacity of the interceptor and the quantity of grease in the waste water. The cleaning interval can vary from once a week to once in several weeks. When this period is determined, we recommend regular cleaning at this interval in order to maintain proper operating efficiency. Solids that collect in the interceptor through settling should also be removed at the same time of the grease removal. At this time the air relief port should be checked to see that it is clear. Complete operating and maintenance instructions are packed with every interceptor.

Even the best designed interceptors that are properly installed will fail if they are not maintained. Maintenance must be performed before the grease in the waste water down stream of the interceptor exceeds 100 parts per million (100 milligrams per liter) or in accordance with local code*. If user must comply with a code which limits grease to 100 parts per million, cleaning is recommended every 2 or 3 days. When cleaning is performed, it should be understood to always include the removal of grease from the top of the separation chamber as well as any solids which have accumulated along the bottom. See Figure 1.

How the Traditional Grease Interceptor Works
The Traditional Grease Interceptor has an external flow control fitting properly sized and installed to regulate the flow into the unit. This allows the grease-laden water to enter at a controlled rate of flow, free of turbulence. The water interacts with strategically located baffles to separate the grease from the water. Once separated, the grease contaminants rise to the surface of the water in the unit by natural flotation and are accumulated until removed. A regular manual cleaning interval must be established for maintaining proper discharge efficiency.  

Traditional Interceptor Guide Specification
The Traditional Grease Interceptor, which is often referred to as a passive or manual unit, utilizes the gravity separation principle. The rate of flow into the interceptor is controlled by a flow control fitting, enabling the interceptor to collect over 90% of the grease which flows into it. “Uni-lock” cover design permits convenient cover removal for periodic cleaning. The interceptor may be set on the floor, semi-recessed or recessed with cover flush with finished floor. Low rough-in designs are available for use with low roughing sinks. The unit is constructed from gray duco coated fabricated steel complete with removable baffles, gasketed cover, external flow control fitting, internal air relief by-pass, cleanout plug and visible double wall trap seal. Available options include lift out sediment bucket and aluminum cover or cover recessed for terrazzo or tile. These units may also be fabricated from type 304 stainless steel.