Airtac PU Straight Fitting PU8
The AirTAC Airtac PU Straight Fitting PU8 is a genuine straight union for push-in tube connection, rated 0 - 1.0 MPa (0 - 10 kgf/cm2) with a 1.5 MPa proof pressure.
- TypeStraight union
- SeriesPU
- 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 PU Straight Fitting PU8
The AirTAC PU8 is a one-touch straight union, the simplest part in AirTAC's resin fitting range: a tube-to-tube coupler that splices two lengths of Dia 8 soft nylon or polyurethane tubing end to end with no thread and no adapter in between. Push each tube home into its chuck and the stainless spring gasket locks it against the POM seal; press the release ring and the tube slides straight back out.
This is the resin spec profile, not the metal line: working pressure 0-1.0 MPa (0-10 kgf/cm2), vacuum down to -750 mmHg, proof pressure 1.5 MPa, and a temperature window of -20 to +70 C. The standard body colour is grey, and the threaded fitting families that share this platform arrive with sealant already applied - on a union there is no thread, so nothing to seal except the two tube grips themselves.
Airtac PU Straight Fitting PU8 Technical Specifications
| Model | Airtac PU Straight Fitting PU8 |
|---|---|
| Type | Straight union |
| Series | PU |
| 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 PU Straight Fitting PU8
| PU | Straight union. |
|---|---|
| 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 PU Straight Fitting PU8 Is Used
Repair splice on a packaging machine
A chafed 8mm line to a carton-clamp cylinder can be cut clean and rejoined with a PU8 in minutes, restoring the circuit without re-plumbing from the valve manifold.
Extending a run on a pick-and-place gantry
When a vacuum ejector or gripper moves further down the gantry than the original hose allowed, a PU8 union extends the Dia 8 trunk line to the new position.
Sectioned air drops along a conveyor
Long conveyor systems take air to each drive unit in stages; PU8 unions link consecutive 8mm hose segments so each section can be disconnected for maintenance.
Is the Airtac PU Straight Fitting PU8 the Right Part?
Sizing ladder: step down to PU6 for 6mm tube on lighter actuator circuits, or step up to PU10 when the run feeds a larger-bore cylinder where flow capacity rises with the bore. The Dia 8 position sits mid-ladder and is the usual choice for mid-size cylinders and valve-to-actuator splices. Whatever you pick, the union grips one tube OD only - a Dia 8 PU8 will not hold 1/4 inch (6.35mm) tube, even though the numbers look close.
Reach for a straight union when both ends are tube and you need an inline splice, extension or repair joint. If one end is a threaded port, you need a PC male connector instead; if the joint must step between two different tube sizes, the PG different-diameter straight is the correct part, not this one.
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 PU Straight Fitting PU8 FAQ
The PU8 is a Dia 8 tube-to-tube straight union on AirTAC's resin one-touch platform. Working pressure is 0-1.0 MPa (0-10 kgf/cm2), negative pressure goes to -750 mmHg (10 Torr), proof pressure is 1.5 MPa, and the temperature range is -20 to +70 C. Use soft nylon or polyurethane tubing of exactly 8mm OD.
No. The PU8 grips Dia 8 tube in both chucks and nothing else. To step between two different tube diameters, use the AirTAC PG different-diameter straight union in the matching sizes - forcing a mismatched tube into a one-touch chuck is the most common cause of a blown-off line under pressure.
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Covers non-human-caused product damage.
Fast Dispatch
Standard parts are processed and dispatched in 3-5 business days.
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Most inquiries answered within 7-8 hours.
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