Experimental liquid densities of cis-1,3,3,3-tetrafluoroprop-1-ene (R1234ze(Z)) and trans-1-chloro-3,3,3-trifluoropropene (R1233zd(E))

•Compressed liquid density of low GWP refrigerants.•Measurements carried out using a vibrating tube densimeter.•Density measurements of cis-1,3,3,3-tetrafluoroprop-1-ene R1234ze(Z) up to 30 MPa.•Density measurements of trans-1-Chloro-3,3,3-trifluoropropene R1233zd(E) up to 25 MPa.•Comparison with other literature data and dedicated equation of state. In this work, liquid phase densities of two fourth generation refrigerants, cis-1,3,3,3-tetrafluoroprop-1-ene R1234ze(Z) and trans-1-chloro-3,3,3-trifluoropropene R1233zd(E), are measured. The densities have been measured using a vibrating tube densimeter over the temperature range from 273.15 K to 333.15 K for pressures up to 30 MPa. For both fluids, the expanded uncertainty at a confidence level of 95% in the density measurements is estimated to be 0.07% over the entire T–p range measured.