Model: FC-4 Dual for quenching furnaces having oil reservoir size of 2,000 to 5,000  gallons, especially for hot quench application. 

FC-4 Dual is the two FC-4 units mounted on the same skid which provide a combination of two different micron filter media sizes. The 1st  FC-4 unit contains filter media size such as 10 micron filters in the 1st unit as a pre-filter prior to the 5 micron filters in the 2nd unit.
Filtration :  FC-4 Dual is designed to remove excessive carbon particulate from quenching oil. There are 3 different filter elements available to choose:

C-5 for 5 micron filter
C-12 for 12 micron filter
C-24 for 24 micron filter  

These filters are low cost element with higher surface area to increase dirt holding capacity.
For Quenching Oil :  The excessive carbon in quenching oil causes stain on part surface and weak spot on metal surface. This heat treated part will eventually deform under stress over a period of time and break prematurely. Embedded carbon on material surface causes inconsistent hardness quality through heat treated material. The quenching speed variation caused by excessive carbon will have negative impact on cooling curve and cooling rate during heat treating process. The continuous filtered quenching oil will reduce furnace corrosion and high maintenance.