Clean room perforated floor panel

A perforated floor panel comprising:

• a. a floor pan comprising:
• a perforated planar floor portion having a top surface and an opposite bottom surface;
• a flange extending downwardly from the periphery of said bottom surface;
• and,
• a ledge formed in said peripheral flange spaced from and generally parallel to the bottom surface of said perforated planar floor portion, said ledge extends inwardly from the portion of said peripheral flange which is adjacent to the periphery of said bottom surface of said planar floor portion and into the space defined by that portion of said peripheral flange adjacent to the periphery of said floor pan bottom surface;
• b. a fluid pervious balancing pad removably disposed within the space defined by said peripheral flange and said floor pan bottom surface, and in abutting juxtaposition with said floor pan bottom surface;
• and,
• c. balancing pad retaining means comprising:
• a peripheral frame member;
• a generally planar grid-like structure of spaced crossed rod members connected to each other at the point of intersection and attached at their ends to said peripheral frame member;
• and
• a plurality of retaining clips spaced equally around and attached to said peripheral frame member, each of said retaining clips comprising:
• a resilient elongated rod attached at one end to said peripheral frame member and having its other end free;
• and,
• a tongue formed between the ends of said elongated rod, said tongue projecting outwardly of said grid-like structure and resiliently nestingly engaging said ledge formed in said peripheral flange to captively hold said grid-like structure in spaced relationship to said bottom surface of said floor pan and captively containing said balancing pad between said floor pan bottom surface and said planar grid-like structure and holding said balancing pad against said bottom surface of said planar floor portion.