A steel disc installed inside an open-head drum that helps keep viscous fluids flowing to the pump inlet. The disc rests on the top surface of the product in the drum. The disc typically includes a seal on its outer rim that wipes product from the inside surface of the drum as the product level in the drum decreases.
The disc also includes a hole in the middle of the disc through which the pump is inserted.
See also PEI/RP700.