Airtac PG Reducing Union PG6-4D
The AirTAC Airtac PG Reducing Union PG6-4D is a genuine different diameter straight for push-in tube connection, rated 0 - 1.0 MPa (0 - 10 kgf/cm2) with a 1.5 MPa proof pressure.
- TypeDifferent diameter straight
- SeriesPG
- Working pressure0 - 1.0 MPa (0 - 10 kgf/cm2)
- Proof pressure1.5 MPa
- Temperature-20 to +70 °C
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac PG Reducing Union PG6-4D
The PG6-4D is an AirTAC PG series different diameter straight union, a tube-to-tube reducer that joins a Dia 6 mm line on one side to a Dia 4 mm line on the other with no threaded port in between. Each end is a one-touch socket: push the tube home and the internal chuck grips the OD, press the release ring and the tube frees off. Because both ends seal on the tube and not on a thread, the only sealing elements in the part are the two NBR O-rings.
This is the standard resin and brass one-touch spec, not the metal BP line: working pressure 0-1.0 MPa (0-10 kgf/cm2), vacuum to -750 mmHg (10 Torr), proof pressure 1.5 MPa and a service temperature of -20 to +70 C with soft nylon or polyurethane tubing. The D suffix gives the fitting a black body, which matters on the PG series - unlike PC and POC connectors, where D changes only the release button, on a PG union the body colour changes with the code.
Airtac PG Reducing Union PG6-4D Technical Specifications
| Model | Airtac PG Reducing Union PG6-4D |
|---|---|
| Type | Different diameter straight |
| Series | PG |
| Connection | Push-in one-touch |
| Working pressure | 0 - 1.0 MPa (0 - 10 kgf/cm2) |
|---|---|
| Negative pressure | -750 mmHg (10 Torr) |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C |
| Applicable tubing | Soft nylon or polyurethane tube |
| Thread standard | PT (Rc tapered) unless the code says otherwise |
POM release button and chuck, aluminium-alloy guide, stainless spring gasket, NBR O-ring; body brass or PBT depending on the part. AirTAC publishes flow as a characteristic curve rather than a single figure, so no L/min value is listed.
Model Code: Airtac PG Reducing Union PG6-4D
| PG | Different diameter straight. |
|---|---|
| 4 / 6 / 8 / 10 / 12 | Tube outside diameter in mm (3.2 mm exists on the mini series). |
| M5 / 01 / 02 / 03 / 04 | Thread: M5x0.8, 1/8", 1/4", 3/8", 1/2" (M3 on the mini series). |
| D | Black. Blank = grey. |
Fitting & Sealing Notes
- check Cut the tube square and clean before pushing it home, or the seal will leak.
- check Push until it stops, then pull back to check the chuck has gripped.
- check To release, press the collet ring fully in and pull the tube out.
- check Threaded parts arrive with sealant on the thread; M5 sizes use a sealing gasket.
- check Match the tube OD exactly - a 6 mm fitting will not hold 1/4" tube.
Where the Airtac PG Reducing Union PG6-4D Is Used
Compact gripper feed on a pick-and-place head
A 6 mm drop runs down the gantry column, then PG6-4D steps it to 4 mm for the last flexible run into a small pneumatic gripper, keeping the moving loop light and kink-free.
Air feed to a benchtop vacuum ejector
Small lab ejectors draw best from a short 4 mm supply; this reducer lets the lab air ring main stay at 6 mm while the final connection to the ejector port drops down in a straight line.
Downsizing branches on a packaging machine manifold
On a cartoning machine where only one small cylinder per station needs low flow, a 6 mm header feeds each station and this union steps the branch down to 4 mm tubing at the point of use.
Is the Airtac PG Reducing Union PG6-4D the Right Part?
Size both ends exactly to the tube OD. This union accepts 6 mm on the large port and 4 mm on the small port; a 6.35 mm (1/4 in) tube will not seat in the 6 mm chuck, and neither end takes a threaded stud. If you need to step a 8 mm trunk down to a 4 mm drop, the next reducer up in this family is PG8-4; PG6-4 sits at the small end of the ladder, so there is no smaller step-down pair below it in the standard range. Flow through the joint is limited by the smaller 4 mm bore, so expect the downstream circuit, not the union, to set the air capacity of the branch.
Choose a PG straight reducer when the line change happens mid-run. If the step-down must happen at a manifold or cylinder port with a thread, you need a male reducer branch such as PKD instead; if the two lines must meet at a corner rather than in line, a PV union elbow is the shape to look at.
Quick checklist
- ✓ Tube outside diameter matches exactly
- ✓ Thread size and standard match the port
- ✓ Working pressure within 0 - 1.0 MPa (0 - 10 kgf/cm2)
- ✓ Temperature within -20 to +70 °C
Airtac PG Reducing Union PG6-4D FAQ
The PG6-4D is a resin one-touch different diameter straight union from Dia 6 mm tube to Dia 4 mm tube, with no thread. Working pressure is 0-1.0 MPa (0-10 kgf/cm2), proof pressure 1.5 MPa, vacuum capability -750 mmHg (10 Torr), and the temperature range is -20 to +70 C. It is for soft nylon or polyurethane tubing only, and the D suffix means the body is black.
No. The large port is machined for 6.00 mm OD tube and the chuck will not grip 6.35 mm tube securely, so the seal would leak or release. Use an exact 6 mm OD nylon or polyurethane tube on the big end and 4 mm OD tube on the small end, and if you genuinely run imperial tube, move to AirTAC's separate inch-sized N-series fittings instead.
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