Resource Centre | Grease Trap Resources
A flow restrictor is a device that is designed to reduce the drainage flow rate so that smaller grease interceptors can be used. They do this by constricting the drainage pipe size between a plumbing fixture and the grease interceptor. We strongly discourage the use of grease interceptors that require a flow restrictor device. Although smaller interceptors cost less initially, the overall lifetime cost is substantially higher than adequately sized interceptors that do not require flow restrictors, and they present a much higher risk of drain problems and sewer-use bylaw infractions (see interceptor sizing).
Flow restrictors can be separate fixture units installed in the drainage system, or integral restrictor gates/plates installed directly on the inlet of small "box" type grease interceptors. Flow restrictors are required wherever small box type grease interceptors are used.