The installation of flow restricting orifices in both the nitrogen gas and instrument air supply lines in the D-Zero Building limits the flow available to the various users. These orifices are strategically positioned along the lines such that no one user can monopolize the gas supply and deprive others of their flow required to operate. Provided that the necessary orifice plates are machined in a manner similar to that of the prototypes, the orifices for the various lines were sized using the discharge coefficient for the round edge orifice because the calculated values were in good agreement with the empirically obtained values for this case. The final calculated orifice diameters for the round edge, sharp edge, and short tube cases are listed in Table 2.