Analyzing the Impeller Eye
Jan 07, 2019· Plain Vane Versus Francis Vane Impellers. Many process pumps use a "plain" vane design. A plain vane has a single degree of curvature. The inlet vane angle (β1) is constant across the width of the vane. This results in lower costs of the pattern and impeller casting but also in slightly lower efficiency and higher NPSHR. A Francis vane has two ...