The Kelvas repair facility was a Cardassian space station located in the Kelvas system in the 24th century.
In 2375, Breen engineers were installing energy dampening weapons aboard Jem'Hadar attack ships at the repair facility. A five-person team from the Cardassian Rebellion was able to infiltrate the station and steal one of the retrofitted attack ships, bringing the weapon back to the Federation for study. (DS9: "Tacking Into the Wind")
The facility was rendered as a CGI model, which was a modification of structures seen in the Monac shipyards in "Shadows and Symbols". The model was later used again in "What You Leave Behind".
was surprised to see the Female Founder in her sector, while she was on Cardassia shortly before, the facility seems to have been in a different sector then Cardassia Prime.