Corrosion Solutions

Virtus offers both an alloy and coating solution to address formicary corrosion. Formicary corrosion occurs in copper based alloys and in the presence of organic acids, moisture and oxygen. Although not visible to the un-aided eye, formicary corrosion appears as a wandering pit which can lead to leaks in the indoor coils of vented AC systems.


Virtus offers two primary solutions effective against formicary corrosion:


UNIGUARD (4221) alloy has been found to be at least 25 times more effective against formicary corrosion than standard DHP (CA122) alloy.

UNIGUARD is patent pending and available in Tube-in-a-Cube® (TIAC®) and hairpin forms.



T-Proof is a coating technology effective against formicary corrosion. Virtus's uniform coating thickness, with X-ray analysis of the tin deposit, assures coating quality. 

Virtus has placed over 100-million T-Proof coated hairpins in the field since 2004 with no reported formicary corrosion failures.

T-Proof is covered under our corrosion warranty for up to 10 years and supplied as Pins-in-a-Bin®.

Product Brochures

New product brochures coming soon.