Reducing Unions - External/Internal

stainless reducing union
External/internal reducing union
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In external/internal reducing unions, the larger size tubing is made up with an external fitting and the smaller size tubing is made up with an internal fitting. In the bulkhead version, the bulkhead nut is on the side with the internal fitting. 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.

stainless bulkhead reducing union
External/internal bulkhead reducing 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. Custom configurations, such as with the external nut on the locking nut side, are available on special request.

Standard external/internal reducing unions

Tubing OD Bore Product No.
1/8" to 1/16" 0.25 mm EZRU21C*
0.75 mm EZRU21
1/16" EZRU21T*
1/4" to 1/16" 0.25 mm EZRU41C*
0.75 mm EZRU41
1/16" EZRU41T*

* Available as a special-order item.
  Also available: 1/16" to 1/32", 1/8" to 1/32", and 1/4" to 1/8"

Bulkhead external/internal reducing 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" to 1/16" 0.75 mm 5/16" EZBRU21
1/16" 5/16" EZBRU21T

* Available as a special-order item.
  Also available: 1/16" to 1/32", 1/8" to 1/32", 1/4" to 1/8", and 1/4" to 1/16"



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