Pipe flow not working right?

[psusi]

I had a perfectly working loop with a liquid reservoir cooling into the cold biome, and cooling the metal refinery when I ran it.  I had some coal gens that were getting warm just above there, so I added some pipes to route the coolant up there via a valve.  It cooled down the gens and I closed the valve, and now the coolant won't flow past the valve and back into the reservoir.  What is wrong here?  The segment in questino has two pipe bridges feeding into it, and either the valve ( now closed ) or the reservoir sinking.  Why is it stuck?

 

[nakomaru]

That section is outlet, inlet, outlet, inlet. You have an outlet (top right bridge) between your two inlets. The top right bridge pushes flow towards the two inlets.

Do this instead.

[storm6436]

Yeah, you can do n sources->Destination and source ->n destinations... so:

s->d good

d<-s good

Similarly:

s->s->d and d<-s<-s good 

s->d<-s and d<-s->d good

but:

s->d<->s->d  as you have on that segment, not so much. 

 I imagine the pipe algorithm starts its mapping from each source, but get's hung in a conflict between the two sources when it computes the overflow mechanic on the left destinaton, which is why it won't flow past.