Unions - External/Internal

stainless external/internal union
External/internal union
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External/internal unions have male threads on one end and female threads on the other, for connecting a standard zero dead volume fitting to an existing tube which already has an external nut made up on it. 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.

stainless bulkhead external/internal union
External/internal bulkhead union
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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 this style of union when connecting to an installed external nut.

Standard external/internal unions

Tubing OD Bore Product No.
1/16" 0.25 mm EZU1C
0.50 mm EZU1M
0.75 mm EZU1
1/16" EZU1T

* Unions for 1/32" and 1/8" tubing available as special-order items.

Bulkhead External/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.
1/16" 0.25 mm 5/16" EZBU1C
0.50 mm 5/16" EZBU1M
0.75 mm 5/16" EZBU1
1/16" 5/16" EZBU1T

* Unions for 1/8" tubing available as special-order items.




With a bulkhead union, an O-ring can be installed between the body and the panel to allow operation in purged environments.