39pcs Pneumatic Fittings Kit – PU / PE / PZA / PY / PV-12 Quick Release Connectors for 4mm Hose

A comprehensive assortment of 39 push-in pneumatic fittings covering the five most commonly needed configurations for 4mm OD tubing circuits. This kit eliminates the need to order individual fitting types separately — providing straight connectors, equal tees, reducing tees, Y-branches, and elbow fittings in a single organized box. Suitable for compressed air, water, and light fluid distribution in pneumatic automation, laboratory, and hobby applications.

Fitting Types Included & Naming Convention

• PU-12 (Straight Union): Inline connector joining two tubes of the same diameter end-to-end. Used for extending tube runs or repairing cut tubing.
• PE-12 (Equal Tee): 3-way tee with all three ports the same diameter. Used for branching a single supply line into two equal branches.
• PZA-12 (Reducing Union): Straight connector joining two tubes of different diameters. Eliminates the need for a separate reducer fitting.
• PY-12 (Y-Branch): Y-shaped 3-way fitting. Similar to a tee but with angled branch ports — reduces flow turbulence at the branch point compared to a 90° tee.
• PV-12 (Elbow / 90° Union): 90° elbow connector for changing tube direction without bending the tube. Prevents kinking in tight routing paths.

The “-12” suffix in these part numbers indicates 4mm tubing OD (not 12mm). This is a manufacturer-specific coding convention — verify tubing OD before ordering.

Key Specifications

• Tubing OD: 4mm (all fittings in this kit)
• Body Material: POM (acetal) or PA66 nylon
• Working Pressure: 0–1.0 MPa (0–145 PSI)
• Temperature Range: 0°C to +60°C
• Media: Compressed air, water, light non-corrosive fluids
• Total Quantity: 39 pieces in assorted types

What Questions Does This Product Answer?

• "What does the ‘-12’ suffix mean in PU-12, PE-12 etc.?" — In this manufacturer’s coding, “-12” refers to 4mm tubing OD, not 12mm. This is a non-standard internal code. Always verify the actual tubing OD compatibility in the product description before ordering.
• "When should I use a PY Y-branch instead of a PE tee?" — Use a Y-branch (PY) when flow direction matters — the angled ports reduce turbulence and pressure drop at the branch point compared to a 90° tee. For low-flow pneumatic circuits, the difference is negligible; for higher-flow or fluid circuits, Y-branches improve flow efficiency.
• "Can I use these fittings for vacuum circuits?" — Yes. Push-in fittings with O-ring seals are suitable for vacuum applications down to approximately -0.09 MPa (-90 kPa / 26 inHg). Ensure all tube ends are cut square and fully inserted for a leak-free vacuum seal.
• "What is the difference between a PZA reducing union and a PEG reducing tee?" — PZA is a straight 2-port reducer (inline size change). PEG is a 3-port reducing tee (two large ports + one small branch). Use PZA to change tube size in a straight run; use PEG to branch off a smaller line from a larger main line.

Typical Applications

• Laboratory & analytical: Gas distribution panels, instrument air supply, chromatography carrier gas circuits
• Aquariums & hydroponics: Air pump distribution, CO₂ line routing, nutrient solution micro-circuits
• 3D printing: Bowden tube routing, multi-zone part cooling, enclosure air circulation
• Pneumatic automation: Compact cylinder supply circuits, vacuum generator distribution, sensor air purge lines
• Hobby & DIY: Airbrush supply lines, model railroad pneumatics, custom fluid circuits

Package Contents

39 pieces total — PU-12, PE-12, PZA-12, PY-12, PV-12 push-in fittings for 4mm OD tubing, supplied in organized storage box.