Internal unions have male threads, requiring a nut with female threads. Standard material is 300 series stainless. Also available in Hastelloy C and gold-plated stainless versions.
Select the union with the bore that matches the ID of the tubing. If the IDs are different, choose the union with a bore which matches the smaller tube bore. (A through-type union is illustrated at right.)
Bulkhead versions are designed to be mounted through an instrument panel or on a bracket. The fitting body is undercut so that it bites into the panel when the mounting nut is tightened, eliminating the need for a lock washer.
Note: Because 1/16" external fittings have very thin, easily distorted walls, they are not as durable as 1/16" internal fittings. We recommend the use of external/internal unions when connecting to an installed external nut.
Standard External Unions
| Tubing OD | Bore | Product No. |
|---|---|---|
| 1/8" | 1.00 mm | EU2 |
| 2.0 mm | EU2L | |
| 1/8" | EU2T | |
| 1/4" | 2.0 mm | EU4 |
| 4.6 mm | EU4L | |
| 1/4" | EU4T |
Bulkhead External Unions
The "Hole" heading in the table below refers to the size of the hole required for mounting the union through a bulkhead or panel.
| Tubing OD | Bore | Hole | Product No. |
|---|---|---|---|
| 1/8" | 2.0 mm | 5/16" | EBU2L |
| 1/8" | 5/16" | EBU2T | |
| 1/4" | 2.0 mm | 7/16" | EBU4 |
| 4.6 mm | 7/16" | EBU4L | |
| 1/4" | 7/16" | EBU4T |