Wins over Italy and the Netherlands, and a loss to hosts Russia, saw Wales qualify for the quarter-finals.
England proved too strong, winning 21-7, but Wales then beat Belgium and Poland in the repechage to claim fifth and book their place on the Gold Coast.
Head coach Nick Wakley can now start preparations for the Commonwealths.
Sian Williams (capt); Shona Powell-Hughes; Dyddgu Hywel; Gemma Rowland; Bethan Dainton; Rhiannon Parker; Ffion Lewis; Elinor Snowsill; Hannah Jones; Philippa Tuttiett; Sinead Breeze; Jasmine Joyce (travelling reserve: Jodie Evans).
Wales Women sevens qualified for the 2018 Commonwealth Games after finishing fifth at the Kazan Sevens, the finale of the Grand Prix Sevens Series.