I just replaced that. It's not a valve, just a connector. I ordered mine from Amazon. It was like $50.
https://www.amazon.com/Genuine-Nissan-92410-EA200-Heater-Hose/dp/B00BFE3BOM
https://www.amazon.com/Genuine-Nissan-92410-EA200-Heater-Hose/dp/B00BFE3BOM