Grease And Oil Traps

Grease in sewers results in the formation of incrustations that are difficult to remove and cause a substantial loss in the capacity of the sewer. Some cities have a basin for the removal of these substances at the sewerage-treatment works.

A general feature of grease and oil traps is the provision of a channel, which forces the sewage to flow downwards, beneath a free surface, while passing through the trap. Floating grease and oil rise to the surface on the inlet side of the trap, from which they may be cleaned through removable covers on the structures. It is essential that the cover be tightly sealed to avoid the escape of odours into the building; and it is preferable that the trap, if large, be placed outside the building itself. The capacity of trap should be about double that of the fixtures draining into it.