Uniweld Nitrogen Flowmeter UNF3

The Uniweld UNF3 is a nitrogen flowmeter for measuring purge flow during brazing and pressure testing.

A flowmeter gives a numerical flow rate rather than a visual indication, which allows the purge to be set to a specified value.

The value matters in both directions. Insufficient flow fails to displace the air, and oxide scale forms. Excessive flow cools the joint so that the filler does not flow properly, disturbs the flame, and can blow molten filler out of the joint, producing a defective connection.

Manufacturers and industry guidance publish recommended purge rates, and being able to set that rate rather than estimate it produces consistent results.

Nitrogen is also used for pressure testing, where a regulator and appropriate gauges control the test pressure. It is used because it is dry, inert, and inexpensive.

The safety point that must be stated is that oxygen must never be used in place of nitrogen for purging or pressure testing. Oxygen in contact with oil under pressure ignites, and refrigeration systems contain oil. This has caused fatal explosions.

Compressed air is also unsuitable, since it introduces moisture and contains oxygen.

Confirm the flowmeter's range and connections suit the work, set the purge flow to the recommended rate, provide an outlet for the gas to escape, and use only nitrogen for purging and testing refrigerant circuits.

Brand

Uniweld

SKU

UNF3

Category

Flow Indicators

Weight

1.8 lbs

Dimensions

7.50" x 4.50" x 3.50"

Price

$70.00

Availability

In stock (9 available)

Rating

0 / 5.0