Hard-sphere compressibility factor Z and hard-dimer radial distribution function at contact g(HD)(sigma) are fit to simple packing fraction eta expressions and are used in the dimer version of Wertheim's perturbation theory to obtain five cubic equations of state (EOS's) for athermal hard-sphere chain fluids. The predicted Z(m) versus eta for various chain lengths m and the reduced second-virial coefficient versus m are compared with simulation data and the original noncubic dimer perturbation theory EOS's. A cubic analog of the Boublik-Mansoori-Carnahan-Starling (BMCS) EOS successfully represents the unlike pair correlation function g(12)(sigma) and Z versus eta for binary hard-sphere mixtures of moderate size difference in the components. The new CTPT-D models are extended to calculate Z(m) versus eta for binary homonuclear hard-sphere chain mixtures. The choice of a suitable EOS dispersion term to simultaneously represent single phase PVT and phase equilibria is briefly explored. A similar TPT approach was used to derive a quartic EOS for Lennard-Jones chain fluids, and Z(m) versus eta isotherms are determined and compared with simulation results for chains up to 100 segments long. The new cubic and quartic EOS's provide a simple foundation for developing equations of state for complex fluids including multipolar and association effects. (c) 2015 Elsevier B.V. All rights reserved.