Airtac PG Reducing Union PG12-8D
The AirTAC Airtac PG Reducing Union PG12-8D 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 PG12-8D
The PG12-8D is an AirTAC PG different diameter straight union in black, joining a Dia 12 mm tube to a Dia 8 mm tube in a single inline body. Unlike every threaded fitting in the one-touch range, the PG carries no port thread at all: both ends are push-in sockets, so the 12-to-8 step happens purely inside the union. Push each tube home and the stainless spring gasket and chuck grip its outside diameter; press the release ring and the tube slides free again.
This is the resin profile, not the metal line: working pressure 0-1.0 MPa (0-10 kgf/cm2), vacuum down to -750 mmHg (10 Torr), proof pressure 1.5 MPa, and a temperature window of -20 to +70 C. Use soft nylon or polyurethane tubing. The POM chuck, aluminium-alloy guide and NBR O-ring are shared across the resin family, and because this is a D-suffix part the body itself is moulded black rather than the standard grey.
Airtac PG Reducing Union PG12-8D Technical Specifications
| Model | Airtac PG Reducing Union PG12-8D |
|---|---|
| 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 PG12-8D
| 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 PG12-8D Is Used
Packaging machine cylinder feed
A 12 mm trunk drop from the air-preparation manifold on a cartoning machine steps to 8 mm at the last metre before a mid-bore take-away cylinder, saving tubing cost without starving the stroke.
Vacuum pick-and-place leg
On a vacuum sheet-handling head running near -750 mmHg, the 12 mm header reduces to 8 mm at each cup station, keeping evacuation time dictated by the cup line rather than the supply run.
Dark-panel machine builds
In electrical cabinets and robot cells finished in black or anthracite, the black D-suffix body blends with the enclosure colour scheme instead of showing a grey plastic joint mid-run.
Is the Airtac PG Reducing Union PG12-8D the Right Part?
Both neighbours sit on the Dia 12 side of the ladder. PG12-10 steps a 12 mm line down to 10 mm and keeps more flow capacity in the branch; PG12-6 drops further, to 6 mm, for light-duty actuator feeds. Whichever step you pick, remember the smaller bore governs the whole run: through a PG12-8D the 8 mm leg is the restriction, so size the downstream cylinder or valve from the 8 mm tube, not the 12 mm supply. And OD must match exactly - a Dia 12 socket will not seal on 8 mm tube or vice versa.
If the step-down also needs a threaded connection into a manifold or component port, the PG shape is the wrong answer: look instead at the PKD male reducer triple branch (only PKD6-401, PKD8-602 and PKD10-803 exist) or a standard PC male connector at each size. The PG is strictly for joining two tube runs of different diameter in line.
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 PG12-8D FAQ
It is a PG different diameter straight union for Dia 12 mm and Dia 8 mm soft nylon or polyurethane tube, with no port thread. Working pressure is 0-1.0 MPa (0-10 kgf/cm2), it draws vacuum to -750 mmHg (10 Torr), proof pressure is 1.5 MPa, and the service temperature range is -20 to +70 C. The D suffix makes the body black; the ratings are identical to the grey PG12-8.
No. One-touch sockets grip the exact outside diameter they are stamped for, so the 12 mm end only holds Dia 12 tube and the 8 mm end only holds Dia 8 tube. The diameter change happens inside the union body itself. If you genuinely need one socket to accept a non-matching tube, that part does not exist in this range - pick the correct reducer code instead.
Authorized Export Seller
Genuine AirTAC parts produced by AirTAC factory.
1-Year Warranty
Covers non-human-caused product damage.
Fast Dispatch
Standard parts are processed and dispatched in 3-5 business days.
Fast Reply
Most inquiries answered within 7-8 hours.
Related AirTAC One-Touch Fittings
Request a Quote for Airtac PG Reducing Union PG12-8D
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.