Fittings, Adaptors and Quick-Release Couplings
Adaptors, tee pieces, banjo bolts, test points and quick-release couplings in the thread and seat combinations a mixed fleet throws up. Identified from the part in hand, because a thread that starts is not necessarily the one that seals.
Features
- Metric, parallel and tapered threads with cone, o-ring and soft-seal seats all appear on one machine, and the adaptor stock has to reflect that rather than pick one system.
- Quick-release couplings are rated for connection under residual pressure or not; using the wrong type is why a coupling will not push home on a warm machine.
- Flat-face couplings are chosen on attachment circuits because they trap less dirt and spill less oil than poppet types when changing a tool.
- Test points let a gauge be fitted without breaking a line, which is the difference between measuring a fault and guessing at it.
- Seat condition matters more than thread condition on a reused adaptor; a scored cone will not seal however hard it is tightened.
Specifications
| Figure | Typical range | Unit | Why it matters |
|---|---|---|---|
| Thread form and size | M18 x 1.5 / G 1/2 parallel | two threads of similar pitch can start and still not seal | |
| Seat type | 24 degree cone with o-ring | the seat, not the thread, makes the seal | |
| Pressure rating | 250 - 400 | bar | an adaptor is often the lowest-rated part of an assembly |
| Coupling face | flat face / poppet | decides dirt exclusion and spill on disconnect | |
| Body material | carbon steel, zinc-nickel plated | plating choice drives corrosion life on exposed couplings |