For the design of tube bundle heat exchangers avoiding tube bundle damage caused by vibration, fluidelastic instability is the most important vibration excitation mechanism, In order to present a guideline in the VDI-Warmeatlas the existing recommendations of CHEN, WEAVER and FITZPATRICK and PETTIGREW and TAYLOR were examined, They differ in the suggested equations for calculating critical velocities for single phase crossflow, With an extensive evaluation and test of consistency of the these and newly available data on this topic, better correlations could be derived, Consistent definitions of critical flow velocity, damping, natural frequency and hydrodynamic mass are used; their values are to be determined in the still fluid with the density rho, Confident documented data show only a small scatter, The other data deviate more, but mainly to the safe side.