DWTA Evaluation Test for Chemical Inhibitors for Central Heating Systems
The Domestic Water Treatment Association is an industry body for companies selling corrosion and scale inhibitors and cleansers for domestic central heating systems. Since no standards were available for these products, the DWTA have developed a test performance standard, which is administered by Build-Cert (the accreditation arm of the WRC-NSF).
The test involves 3 parts:
A corrosion test using rotating bundles of mild steel, aluminium, copper, brass and aluminium coupons in glass cells and tested under temperature cycling in inhibited solutions in standard hard and soft waters with differing aeration. A scaling test using stainless steel heater sheaths over cartridge type heaters placed in the inhibited solution in standard hard water. An elastomer compatibility test involving assessing the volume swells on 4 rubbers immersed in concentrated solutions of the inhibitor.
Midland Corrosion (Corrosion & Environmental Services Ltd.) have been certified by Build-Cert to carry out this test after being audited to BS EN 17025. As of June 2007, we are the only independent laboratory to have gained this accreditation.
