Internal unions have female threads and a fitting detail for zero volume fittings. The nuts have male (external) threads. Standard material is 300 series stainless. Also available in Hastelloy C, gold-plated stainless, and titanium 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.
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.
Standard Internal Unions
| Tubing OD | Bore | Product No. |
|---|---|---|
| 1/32" | 0.15 mm | ZU.5XC |
| 0.25 mm | ZU.5 | |
| 0.50 mm | ZU.5L | |
| 1/32" | ZU.5T | |
| 1/16" | 0.15 mm | ZU1XC |
| 0.25 mm | ZU1C | |
| 0.50 mm | ZU1M | |
| 0.75 mm | ZU1 | |
| 1.0 mm | ZU1L | |
| 1/16" | ZU1T | |
| 1/8" | 0.75 mm | ZU2 |
| 2.0 mm | ZU2L | |
| 1/8" | ZU2T | |
| 1/4" | 0.75 mm | ZU4 |
| 4.6 mm | ZU4L | |
| 1/4" | ZU4T |
Bulkhead Internal 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. |
|---|---|---|---|
| 1/32" | 0.15 mm | 5/16" | ZBU.5XC |
| 0.25 mm | 5/16" | ZBU.5 | |
| 0.50 mm | 5/16" | ZBU.5L | |
| 1/32" | 5/16" | ZBU.5T | |
| 1/16" | 0.15 mm | 5/16" | ZBU1XC |
| 0.25 mm | 5/16" | ZBU1C | |
| 0.50 mm | 5/16" | ZBU1M | |
| 0.75 mm | 5/16" | ZBU1 | |
| 1.0 mm | 5/16" | ZBU1L | |
| 1/16" | 5/16" | ZBU1T | |
| 1/8" | 0.75 mm | 7/16" | ZBU2 |
| 2.0 mm | 7/16" | ZBU2L | |
| 1/8" | 7/16" | ZBU2T | |
| 1/4" | 0.75 mm | 5/8" | ZBU4 |
| 4.6 mm | 5/8" | ZBU4L | |
| 1/4" | 5/8" | ZBU4T |