Table 2.

Formulas used for calculation of effective diameters and MCV sizing thresholds for annular area and diameter

	Formulas used for calculation of effective diameters	Formulas used for calculation of MCV sizing thresholds
Cross sectional area	${\text{D}}_{\text{A}}=2\times \sqrt{\left(\frac{\text{cross-sectional area}}{\mathit{\pi }}\right)}$	$\text{Cross-sectional area}=\frac{\mathit{\pi }\times \text{diameter}{}^2}{4}$
Perimeter	${\text{D}}_{\text{P}}=\frac{\text{perimeter}}{\mathrm{\pi }}$	$\text{Perimeter}=\mathit{\pi }\times \text{diameter}$

D_A effective diameter derived from annular area, D_P effective diameter derived from annular perimeter