[TU-211867] Dupes only apply gas valve setting when it is built and its setting first changed on empty pipe

Okay, thanks for letting us know. I'll take a look and see if I can reproduce.

Can I get you to post your save file so I can take a look at it?

Okay, I tried to build the valve the way I described it in my last save and it worked. So I'm not sure anymore about the "safe approach to build a non-working valve", all I can say I built them this way in between the main pipe and the hydrogen generator and they kept failing constantly. Reloading the save, restarting the game, deconstructing them and building them again, nothing helped until I used the approach I described above.

I'm attaching two saves, one from cycle 202 with non-working valves (there are two, one near the fertilizer makers, one above the water pool), the other from cycle 210 with them fixed.

The Inspiring Friends Cycle 202.sav

The Inspiring Friends Cycle 210.sav

Having the same issue. I wanted to be able to stop flow of a Hydrogen cooling pump for a few cycles to conserve energy by completely halting the flow. It allowed me to switch to 0 right after I built it to full some time later, but won't let me set it to 0 again.

In my case I placed the valve over an existing line of pipes, which were deconstructed before the valve was finished. Then I reconnected the pipes.
I can provide a save file, if necessary.

I made a few more experiments (not nearly comprehensive, I don't have that much time):

1/ Valve on empty pipes - works

2/ Valve inlet on full pipe, outlet on empty pipe that's not connected to anything - doesn't work

3/ Valve inlet on full pipe, outlet on full pipe (flow stopped by next valve) - doesn't work

4/ Valve on pipe, gas passing through continuously - usually doesn't work but may work if there's a gap in the incoming gas.

I made a circuit of two valves sending gas to each other. I couldn't set the valves while I was building the circuit since I connected it to a live pipe and it got full of gas up to the second valve. But once I closed the circuit and the gas started flowing in circle (the pipe wasn't completely full), a dupe suddenly came and adjusted one of the valves. I assume it came exactly at the moment when something was empty around the valve. After that no luck, no further adjustment succeeded since that adjustment reduced the flow and the pipe became full of moving blobs of gas.

I've been having this issue as well. From experimentation, it's when the pipe flowing into the valve is flowing at maximum capacity. So basically, if the valve is just splitting flow (e.g. it can flow somewhere else, skipping the valve), then the valve can always be adjusted. However, if the pipe's only outlet is the valve, and it ever gets backed up or reaches maximum capacity, then the valve can no longer be adjusted (as long as the maximum flow continues into it).

My workaround so far has been adding an outlet before the valve until non-maximum flow reaches the valve.

This should be fixed in today's hotfix(221295).