Brass Push-In Tube Fitting, 0.25 Tube OD to 1/4-18 Male NPT Swivel, Branch Tee

Polyurethane tubing is actually one of the primary uses for this fitting, as long as it's 90 durometer or higher. Polybutylene and soft metal tubing are also compatible. Just push the tube in and the internal gripping teeth lock it in place while the Buna-N O-ring seals against the outside diameter of the tube. No tools needed for the tubing connection itself, though straight connectors do have an interior hex if you need to tighten with an Allen key.