A pressure vent

[Kasuha]

I have a set of showers and lavatories and I want to be sure their output pipes never get full. I also have a set of fertilizer makers and I want to be sure their input pipes are always full so they have enough material to work on all the day and night. This means I need all output from showers and lavatories needs to go to the fertilizer makers, but then all excess needs to be dumped somewhere. And I want to make sure that as little as possible is dumped to keep the makers busy.

A pressure vent would be a (preferably passive) device that has one input and two outputs, and sends all input to one output unless that output is full, then it starts sending the input to the other output.

Here is an image how I solved it in my base, though the solution is a bit clunky. There are four pipe bridges which in total steal 15/16 of whatever comes through the pipe, letting the rest (or whatever's above them being full) go forth to the purifier. It would be nice to have just one device to do the trick, though.

[Masterpintsman]

Route the pipe over the input of the bridge (instead of having a junction before it) and it should consume everything coming it's way till the output pipe is full (and only then let matter packets pass on through the pipe).

[Kasuha]

1 hour ago, Masterpintsman said:

Route the pipe over the input of the bridge (instead of having a junction before it) and it should consume everything coming it's way till the output pipe is full.

Okay, I did not try that because I had experience from the past that such circuits behave strange ... but I still have to put a pipe bridge or a valve in there to get the function right, and having dedicated device for the purpose would feel less like cheating or using side effects of the game design.

[Masterpintsman]

It feels to me that the bridge does the job correctly and without cheating, as it functions the same as a vent in the same place (grab everything from the pipe and let stuff only pass in case it's overpressurized).

[Kasuha]

To me it would make more sense if an inlet or outlet attached to the pipe in given tile acted as a connection in fifth direction (perpendicular to screen). The pipe is going around the machine, not through it so the junction should alternate appropriately all connections at given tile, one of them being from/to the device.

[Masterpintsman]

I think it's good as-is, as it allows for setups that benefit from the functionality of a pressure valve - without the need of a specialised building.

[Kasuha]

Well the whole piping system is not very good. An output port in line with the pipe will get blocked by contents of the pipe, for instance. If there are inputs and outputs interleaved, or if there are loops on the pipe, the pipe gets "confused" where to send its contents. A dead end pipe will keep its contents forever, you need to build something at the end of the pipe to get it empty.

And when one or more of these issues gets fixed, we may lose this convenient function of input directly on the pipe as a byproduct. That's why I don't like it.