Page 153 - Facility Piping Systems Handbook for Industrial, Commercial, and Healthcare Facilities

SOLID-LIQUID SEPARATION AND INTERCEPTORS

SOLID-LIQUID SEPARATION AND INTERCEPTORS 3.21

installations. Second is the semiautomatic type, in which the grease stored in the top of the
unit is discharged through a special valved connection into a separate container. This is
done by running hot water through the unit for the purpose of removing the stored grease.
Third is an automatic unit that continuously removes grease from the effluent. This type is
only used for very large amounts of grease in large projects. A fourth type uses enzymes
added to the grease trap to break up the grease inside the unit and allow it to directly enter
the sanitary piping system.
The grease trap can be placed either under the floor or above the floor, depending on space
conditions available and method of grease removal preferred. The semiautomatic removal
requires an above-the-floor installation, usually under a sink or in a storage room.
The most common material used for a grease trap is cast iron, although steel can be used
for less server service. Refer to Fig. 3.6 for an illustration of a typical grease trap. Figure 3.7
illustrates typical grease trap installations.

FIGURE 3.6 Grease trap.

FIGURE 3.7 Typical grease trap installations. (a) On floor, (b) under floor.

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