ASME A112.14.3 Type C

Flow control fittings ensure 90% or more grease retention efficiency of the interceptor. When consideration isn’t given to the flow rate of the waste water to be handled, the actual flow rate through the interceptor usually exceeds its rated maximum. With such flow rate, the interceptor would be overloaded. Retention time within the unit would not be sufficient for maximum separation. The result would be low efficiency, and pollutants left in the waste water would pass through the interceptor, making the installation less than effective. When the flow is controlled by use of a MIFAB® flow control fitting so that it can never exceed the maximum rating of the interceptor, and the interceptor is cleaned on a regular basis, the maximum pollutant retention efficiency will be achieved and maintained. All external flow control fittings are built with an air intake and should be connected to the vent stack or vent not lower than the flow level of the highest drain serviced or terminated in a return bend at the same elevation outside of the building. A vented flow control fitting improves the efficiency of the grease interceptor by introducing air into the body of the interceptor. As the air bubbles rise to the surface, they are coated with grease. This process brings grease to the surface faster, and, as a result, increases the efficiency. The external flow control fitting furnished with PDI certified interceptors must be installed ahead of the interceptor in the waste line beyond the last connection from the fixture and as close as possible to the underside of lowest fixture. When waste of two or more sinks or fixtures are combined to be served by one interceptor, a single flow control fitting should be used. Air intake for flow control may terminate under sink drain board as high as possible to prevent overflow or terminate in a return bend at the same height and on outside of building. When fixture is individually trapped and back-vented, air intake may intersect vent stack. All installation recommendations subject to approval of the local Code Authority.