Another option and one that would allow you to mirror the Swedish usage done/served two stretches, etc.
As Matt says, there are several options, as well as different options for the UK and the US.

Oxford Dictionary of Modern Slang
Imprisonment; a prison sentence bird; birdlime; bit; carpet; double sawbuck; fall; handful; hard; jolt; Kathleen Mavourneen; lag; moon; neves; newspaper; Paddy Doyle; pontoon; porridge; rouf; sawbuck; seg; sleep; sixer; solitary; spot; stage; stretch; taxi; time; trey; trick
https://books.google.co.uk/books?id=KT-cAQAAQBAJ&pg=PA382&dq...

13 sentence/​term of
lagging, time, bird-lime, penal, bit, spot, sleep, jolt, prison sentence, bird, rap, trick, fall, stretch, custodial sentence, porridge
http://historicalthesaurus.arts.gla.ac.uk/category/?type=sea...

Dictionary of Crime: Criminal Justice, Criminology, and Law Enforcement by Jay Robert Nash
do a bit To serve a short jail sentence. AKA: do a hitch; do a jolt; do a piece; do a stretch
https://www.google.co.uk/search?complete=0&biw=927&bih=845&e...

http://www.eurekaencyclopedia.com/index.php/Category:Custodi...

White Jazz by James Ellroy
Mickey Cohen-perpetual scuffler-two prison jolts. Dead – heart attack, '76
https://books.google.co.uk/books?id=p8VMgoWcmVMC&pg=PA402&lp...
Mickey Cohen – den kämpen–två voltor. Död – hjärtattack evige 1976
https://books.google.co.uk/books?id=ms3KBQAAQBAJ&pg=PT395&lp...

Possibly also of interest, from Resandefolket by Bo Hazell
volta = gå, promenera, resa; gång ...
Används även om fängelsestraff: »Jag går (gör) min andra volta(omgång, »resa«) på fängelset.«
https://www.google.co.uk/search?complete=0&biw=927&bih=873&t...