It is shown that the systems ADS 1315, 3608, 3824 and 3991 are not triple but quadruple. The two new triple systems are ADS 6646 and 8861. The spectroscopic orbit of ADS 1849A is recalculated using new data. Radial velocity measurements indicate that there are no other close spectroscopic components in these systems (with possible exception of ADS 8861B), and current knowledge of system composition is complete. Even if there are faint undetected visual components, their possible orbital parameters are severely constrained by radial velocity data and the availability of empty hierarchical levels. So, this study can be considered as a step towards the definition of a new sample of systems with known degree of multiplicity.
The author is grateful to the personnel of the Simeis observatory for the possibility to use the 1 m telescope and to M. Mayor who made available CORAVEL. Some measurements were secured by my colleagues M. Smekhov and N. Samus. The database SIMBAD operated by the University of Strasbourgh was consulted. This work was partially supported by the grant from Russian State Committee of Science and Higher Education and by the grant MPB000 from the International Science Foundation.