I needed to replace the sprayer type sprinklers in my environmental septic system. The Kikuyu grass grows tall and it is hard to see the location of the tiny sprayers. I designed a T connector that presses into a piece of 19mm poly pipe, used as a riser. Printed in orange prusament it is easy to see in the long grass. I also designed a variable dripper type sprinkler with a spike. Its design is based on looking at an existing sprinkler I have, but can't find in the shops anymore. These are also printed in orange for visibility but I have a lot printed in black PETG. These are in use in the vegetable garden and have been working great. I have included this file as well. There is also a bottom connector that clips to the supply pipe (25mm poly). It supports the 19mm riser and the 4mm pipe connection.
I experimented with thinner 4mm connectors but have gone back to thicker ones. You just need to soften the 4mm pipe with hot water when attaching. It makes a much stronger connection.
I print the drippers at 0.15mm quality and the rest at 0.2mm speed. I designed it all so no supports are needed, the picture of the parts on the bed show the orientation I use to print. I have been printing the bottom connector and dripper spike with a brim lately as I have had a couple detach mid print.
The author hasn't provided the model origin yet.