LaLiga side would prefer a loan agreement with a purchase option, though it is now understood that it is likely to be an immediate permanent transfer with Coquelin agreeing a four-and-a-half year deal.
A new contract signed past year means Arsenal collect a sizeable fee.More news: Tesco shares plunge despite Christmas sales growth
Coquelin admits he spoke to Arsenal team-mates Shkodran Mustafi, Nacho Monreal, Hector Bellerin and Santi Cazorla about life at Mestalla before making the move.
"They all said that Valencia is a great city and a big club, so I am very happy to be here", he told the club's official website.
Coquelin joined from French side Stade Lavallois in 2008 and went on to make 159 appearances for Arsenal.More news: Super Mario Odyssey update will add minigame and other cool features
"He is a fantastic player with lots of potential still to come, he is a joy to coach and he is a good teammate for all our players and he works very hard".
"He goes to Valencia because he didn't get enough games with us this season and he had an opportunity".
"What he is doing at the moment will help him develop as a player because he plays in a different position but at some stage I will play him in at defensive midfield".More news: Riots in Pakistan over killing and murder of 8-year-old girl
Coquelin spent nearly a decade at Arsenal after joining the Gunners in 2008 from French side Stade Lavallois.