Now that the load error is fixed, the mod functions, however when selecting either the "Pipe to Ground 2" or "Pipe to ground 3" recipe and craft, it just stacks with, or as, the regular base game "Pipe To Ground", so the variations are not accessible to use.

Can you try opening the console and type in

/c game.player.force.technologies["steam-power"].researched = true

This should reenable the steam power technology. You can also try to disable it first (by changing true to false) and then reenable it.
All i can say is that it works on both test saves i use.
Maybe another mod is conflicting?

Error in pipe.lua line 71:

"results ='" should be "recipe.result ="

otherwise it just produced regular "Pipe to Ground"

result = ... is obsolete and will trigger an error so one have to use results = {...}
as you can read here:
https://lua-api.factorio.com/latest/types/MinableProperties.html#results

Tried console command on SA save, changed nothing (false then true). Started a new SA save, only this mod active... same result. "Products: 2x Pipe to ground". I'll just stick to vanilla pipes and say I tried. Thanks for your assistance.

Sorry that i cant help and thank you for trying.

result = ... is obsolete and will trigger an error so one have to use results = {...}
as you can read here:
https://lua-api.factorio.com/latest/types/MinableProperties.html#results

No...not that API
I think you missed to put line 'recipe.' in front of results
I just changed line 71 in pipe.lua to:
recipe.results = {{type = "item", name = name[i], amount = 1}}
Works flawlessly with no error. Maybe temporary fix?

Valhingen, thank you. changing the pipe.lua as above fixed the problem for me.

Oh, right! This should go into the recipe table.
I just wonder why it did still work on my end?
I willl update it as soon as i can and fix the weird visual indicator in the T-piece.
Thanks for pointing this out ^^

EDIT:
As for the indicators: fixed