Airtac BU Double Female Thread Straight Connector BU0303-S
SUS304 stainless variant (-S)The AirTAC Airtac BU Double Female Thread Straight Connector BU0303-S is a genuine double female connector rated to 3.0 MPa proof pressure and 0 to +150 °C, for joining threaded pipe runs.
- TypeDouble female connector
- SeriesBU
- Working pressure0 - 1.0 MPa (0 - 10 kgf/cm2)
- Proof pressure3.0 MPa
- Temperature0 to +150 °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 BU Double Female Thread Straight Connector BU0303-S
The BU0303-S is a double female connector: a short union body with a 3/8in PT female thread on each end, used to join two male-threaded ports or nipples face to face without any intermediate fitting. In this -S variant the whole body is machined from SUS304 stainless steel, not the nickel-plated standard finish, so the part suits wash-down plant, marine air and any line where copper in the wetted path is unwanted.
What sets this family apart from a push-in resin connector is the pressure and temperature envelope: 3.0 MPa proof pressure and a 0 to 150 C working range, with vacuum capability down to -750 mmHg. Because there is no tube and no elastomer gripper in the flow path, the union sits happily close to ovens, dryers and mould-temperature equipment where a one-touch resin body would soften.
Airtac BU Double Female Thread Straight Connector BU0303-S Technical Specifications
| Model | Airtac BU Double Female Thread Straight Connector BU0303-S |
|---|---|
| Type | Double female connector |
| Series | BU |
| Connection | Threaded both ends |
| Body material | Stainless steel 304 (-S variant) |
| Working pressure | 0 - 1.0 MPa (0 - 10 kgf/cm2) |
|---|---|
| Negative pressure | -750 mmHg (10 Torr) |
| Proof pressure | 3.0 MPa |
| Temperature | 0 to +150 °C |
| Thread standard | PT (Rc tapered) unless the code says otherwise |
Nickel-plated metal body. AirTAC does not publish a per-part material breakdown for this family. This family is rated to 150 °C, but the TUBE is usually the limit - confirm your tubing's temperature rating before running it hot. Stainless (-S): SUS304 body throughout, for copper-free and corrosive environments. Pressure and temperature ratings are unchanged from the nickel-plated version. AirTAC publishes flow as a characteristic curve rather than a single figure, so no L/min value is listed.
Model Code: Airtac BU Double Female Thread Straight Connector BU0303-S
| BU | Double female connector. |
|---|---|
| 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. |
| -S | Stainless-steel body. |
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 BU Double Female Thread Straight Connector BU0303-S Is Used
Laundry and garment steam-adjacent plant
Joins 3/8in PT air and condensate-takeoff lines running beside ironers and steam presses, where ambient heat above 70 C rules out resin one-touch bodies.
Plating line copper-free circuits
The all-SUS304 construction keeps copper out of the wetted path on electroplating and chemical dosing air lines around 3/8in threaded drops.
Food wash-down bracketry
On bakery and dairy conveyor frames hosed down each shift, the stainless union resists caustic spray at the 3/8in leg-to-valve connection.
Is the Airtac BU Double Female Thread Straight Connector BU0303-S the Right Part?
Step down to BU0202-S when both ports are 1/4in PT male, or up to BU0404-S for 1/2in - those are the only neighbouring sizes AirTAC makes in this stainless double female ladder, alongside the 1/8in BU0101-S. Stepping a size changes the thread engagement and the spanner flats, so check both mating nipples before ordering. BU parts are always equal-size both ends; if you need a 3/8in female landing on a different male size, that is a BD job, not a BU.
If one of the two ports is actually redundant, an honest alternative is BZ03, the 3/8in hexagon head cap plug, which blanks the port outright instead of joining it to anything.
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 0 to +150 °C
Airtac BU Double Female Thread Straight Connector BU0303-S FAQ
It is a double female connector with a 3/8in PT female thread on both ends, body in SUS304 stainless steel. Working pressure 0-1.0 MPa (0-10 kgf/cm2), negative pressure to -750 mmHg, proof pressure 3.0 MPa, operating temperature 0 to +150 C. There is no tube side; both ends are female threads of the same size, as on every BU part.
AirTAC publishes no tightening torque for this family. Apply a suitable thread sealant or PTFE tape to the male threads of both mating parts, then wrench the union up to a firm taper-seat engagement on the 3/8in PT threads and stop - over-wrenching a stainless body can distort the female thread and crack the sealant bed. Pressure-test the joint before putting the line into service.
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 Fittings & Tubing
Request a Quote for Airtac BU Double Female Thread Straight Connector BU0303-S
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.