Uniweld Nitrogen / Contents O N-40 40

The Uniweld N-40 is a 40 cubic foot nitrogen cylinder supplied for refrigeration purging and pressure testing.

Nitrogen is the working gas for two operations that determine whether a refrigeration installation lasts.

The first is purging during brazing. A low continuous flow through the tube displaces oxygen, preventing the black cupric oxide scale that otherwise forms inside heated copper. That scale flakes away in service and circulates, blocking metering devices and strainers and contaminating the compressor.

The second is pressure testing, where nitrogen is used because it is dry and inert. Testing with anything that carries moisture introduces the contaminant the subsequent evacuation is meant to remove.

Cylinder size is a working decision. A 40 cubic foot cylinder is portable enough to carry to a rooftop or through a building, and holds enough for a reasonable amount of work. Larger cylinders reduce changes but become difficult to move.

Nitrogen cylinders are filled to high pressure, and the full cylinder pressure appears at the regulator inlet. A system must never be exposed to unregulated cylinder pressure.

Cylinders must be secured upright at all times, fitted with valve protection caps when not in use, and moved with a cart rather than dragged.

Oxygen must never be substituted for nitrogen in purging or testing, as the combination with system oil has caused fatal explosions.

Brand

Uniweld

SKU

N-40 40

Category

Nitrogen Cylinders

Weight

24 lbs

Dimensions

22.00" x 6.80" x 6.80"

Price

$53.00

Availability

In stock

Rating

4.5 / 5.0