The question is in the title... More of a demand really, it makes it hard to tell how much fluid I have in a system when it's constantly jumping around at random between different tanks, I've tried setting the tanks to input only and using a screwdriver to force fluid out of a tank but that doesn't work. And I want there to be something akin to how for electricity we have the diode block, a kind of one-way fluid valve that can control throughput, and also preferably, ports on the tanks with dedicated input/output markings.

it would be a fluid diode
🤓 technically that would be a Tesla Valve