Is a check valve needed when separating non filtered from filtered water for a conditioning media tank use ?

[bikeboy]

I'm installing a basic carbon water filter to filter chlorine from a city water supply. I've tee'd a line to all outside faucets ahead of the filter tank on the supply before entering line side of filter tank to not filter outside water. I'm assuming i'll have to install a check valve of sort to stop backflow from filter tank. I'm assuming a flapper type would be more efficient than a spring unit for better flow but orientation pedicular (only horizontally) operable.

Please reply if can help;
Thank You...

 

[Geofd]

You want to install a check valve so while your in bypass it doesn't siphon water from the filters when by passed , never seen it done that way but that would work, bothe check valves will work, you might lose a lb or 2 in pressure if you use a spring check