What kind of check valve is used to prevent the return water?

I have to use a check valve to prevent return water due to pipe installation problems due to regular water supply. But the recent discovery of a running water phenomenon, just on a full tank of water slowly from the pipeline flow away, but not all go, a flow did not flow, time is not the same, but sometimes sometimes does not flow, this is going on, ask professional personage answer

Answer:

The problem can't be solved: if you change the pipe, you'll have a vertical check valve

You should be horizontal check valve, with pressure difference, water pressure is not lost; or a check valve inside where the card, must be a certain pressure to baffle back.

You should be horizontal check valve, with pressure difference, water pressure is not lost; or a check valve inside where the card, must be a certain pressure to baffle back.The problem can't be solved: if you change the pipe, you'll have a vertical check valve