Liquid bridge working when blocked

I think you refer to the bridge coming from the pump, crossing the petroleum line?

As far as i can see, there is very little water coming down that pipe. Bridges itself are some kind of mini-storage. They can store a decent amount before the pipe behind it will fill up. And yes it wont show you, whats inside. To make it even worse, deconstructing bridges wont release the stored content. 

I´m sure, if you build something at your open end of the line, the water will appear once again.

Probably you're right

Bridges don't store liquids. It simply transfer what's at it's input, directly to the output.

 

@Smellz : your issue may be due to some water in the slickster room. have this amount of petroleum on 8 tiles, but not on the 2 iltes of the pump. So, maybe you have some water in this pool.

@Gwido, yes, it's true. It's due to some strange behaviour of airlock behind steam room, steam teleports and condensates in neighbouring rooms (one with slickers and one with oil refinery) instantly as duplicants pass the last doors of airlock behind steam room even though these rooms are sealed at given moment. But it's a whole different bug.

So it's related to this bug ?