Problem: a lot of pipes with same appear causes confusion
Suggestion: You should create a system whit arrows (like insertor drop position) that appear when the player put the cursor on pipe. That arrow wold show the possible connections (right, left, reverses...).

Are you running on low or high graphics settings?

On low the pipes appear to be the regular one. This is to reduce overhead needed for graphics memory, as each entity has four sprites, and there's four entities for each type of custom pipe to ground (1 to 1 or 1 to 2 L, etc). I can create a low res version to help that issue.

With just my mod, you're already loading an additional 85 sprites on High res, and only 2 additional on low.

You're right, sorry. But make a low graphic version could be a good idea.

Ok. I could do it fairly quick. Not sure how easy it would be to see. I'll check it out tonight with GIMP.

Was mostly trying to keep the overhead down for low end systems to be performance friendly.

I appreciate the feedback!!

I want to suggest create a pipe version of Bob's Ajustable Inserts version whit pipes too. Maybe use a fusion of this mod whit Flow Control Pipes mod. I know that It's ambitious but it's a idea to think. I don't understand programming, but if Bob got, you should ask help for he.

Unfortunately the engine does not allow anything like that. I would love to. Fluid box connections are built into the entity and cannot be altered during runtime.

Basically, the different underground parts are just different actual entities that have different pipe-connections preset.

Perhaps a gui to allow picking the direction or amount of ports. (All this would do is place the proper pipe down from your inventory and rotate it to the direction you picked)

That's actually an interesting concept. I like the idea.

well, imagine a image of a underground pipe with forward up and whit 4 select box in each direction. Depending of whit are the select box, the underground pipe selected appear instead the vanilla. And (like the Flow Control Pipe) when it's mining, add to inventory the vanilla underground pipe.

I was planning on adding check valves, topoffs, and overflow valves underground as well as underground storage tanks that you can drive over.

There was a mod (that not exist anymore) that the creator use the ceiling of a normal tank to create a underground tank.

About the Valves, a lot of mods use old entities parts (like old boiler) in new entities (like chemical furnace). You may create a underground valve whit appear like top of old boiler with symbol that show the type of valve. Bellow the select box that I described, the player should select the kind of valve clicking on buttons whit symbol of that valve wold be . About the programming, The Flow Control mod created this valves (https://mods.factorio.com/mod/Flow%20Control), if you make the fusion, it's not a problem.

Maybe (I don't know how) the program could use the information of pipe that the play have in hand to select the kind of pipe (underground pipe, underground junction or normal pipe) and "select the material" of pipe in bob's mod (if the player have a plastic underground pipe, the program search a select advanced underground pipe makes plastic). The image of pipe on center of selected boxes should change to pipe that player have selected to put. The Bob's Advanced Incertor work that form, different insertors can use the same configuration of pickup and drop position.

More one suggestion: change the image of underground mini pump to a image of a vanilla pump whit output for down, and whit out the pipe stopper. I think that would look likes better.

Underground valves may likely just be skinned pipe-covers with their symbol on the top. I would color code it instead of a white arrow to make them super easy to see different. I do like the idea of having it just change the type of valve instead of having different recipes. I'll experiment with this. More than likely it will be different recipes since different valves are actually made in different ways from each other.

My plan for underground tanks was exactly what you said, though I didn't even know someone else did it. I was just going to mask the current tank and clip off the bottom portion only leaving the roof and making the flat to the ground.

Inserter entities have custom vectors. What this means is you can adjust their insertion point and drop-off point and even point it in random directions around the base. For pipes I have to make a new entity for every different variant that requires an underground port in a different direction.

To add in his mod, someone would have to take all of my entities and create new sprites under his colors, with his permission. Once done I could build out the database of required entities.

For the mini pump I'm still experimenting with designs. I just wanted something in there for now. I'm gonna have to find a way to mesh it to the ground better, and make it look pipe-ey.
I might be adding a regular sized pump that's all underground to the game, along with probably a mini storage tank.

I tested something today to try to get sprites to draw on it instead. No luck. Will continue to work on it.

On the other hand, I added all the pipes into normal and below res. Anything below normal becomes impossible to read the direction. I also fixed that annoying pump animation.