TESTING THE CORROSION PROTECTION OF HEAT-TRANSFER FLUIDS .1. CHEMICAL, SCREENING AND SPECIAL TESTS

As supplement to AGK Arbeitsblatt W 1 ''Corrosion testing in heat-tran sfer fluids of solar heating installations'' the different methods app lied for testing the corrosion protection in heat-trans fer fluids pro vided with anti-freeze mixtures on glycol basis have been checked. The coupon tests corresponding to ASTM D 1384, the EMPA-Test, special tes ts according to ASTM D 4340 as well as the FVV-Heat-Test were part of these investigations. The investigations were carried out with steel, cast iron, two wrought aluminium alloys, one cast aluminium alloy, wit h copper and brass as well as with tin solder in non inhibited as well as inhibited heat carriers. The non inhibited heat-transfer fluids we re composed of water with ethylene and propylene glycol, the others we re made up with anti-freeze concentrates prefabricated by well known p roducers. All investigated products proved excellent protective qualit ies against corrosion. The coupon test according to ASTM D 1384 has be en the most effective of all methods tested up to now. This article wi ll be continued.