Background
BV42 (Sulphamic acid) is under test to determine if it is a viable descalant for a calorifier containing aluminium. This is usually used in combination with BV41 (Sulphamic acid inhibitor) as an inhibitor.
Investigation
Using aluminium coupons, the corrosion of aluminium has been compared between an inhibited solution containing BV42 at 10%, BV41 at 2% and an uninhibited solution containing 10% BV42. A test was performed in 10% BV42 and 2% BV41 after pre-treatment in a weakly acidic solution of BV41.
Preliminary investigation
Test One was performed by submerging an aluminium coupon in a 10% solution of BV42 at 42°C for 1 hour. This was then cleaned, dried, and weighed.
Test Two was performed by submerging an aluminium coupon in a 10% solution of BV42 dosed at 2% with BV41 at 42°C for 1 hour. This was then cleaned, dried, and weighed.
Test Three was performed by submerging an aluminium coupon in a weakly acidic solution of 2% BV41 for 1 minute, then a 10% solution of BV42 dosed at 2% with BV41 at 42°C for 1 hour. This was then cleaned, dried, and weighed.
Investigation - Coupon visuals
Top Left - Control Coupon
Top Right - Test One
Bottom Left - Test Two
Bottom Right - Test Three
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Data
Discussion and Conclusion
Both the visual inspection and the weight data show that little to no corrosion occurs when Aluminium is exposed to the BV42 solution. The presence of the BV41 causes the aluminium to corrode slightly more that the uninhibited solution, this effect is more pronounced on the coupon pre-treated with the BV41 solution. Therefore, the use of Sulphamic acid, at prescribed concentrations and contact times has very little affect on the Aluminium.
Descaling products
Descaling products can be a good addition to the overall treatment approach of water systems, for more information follow the link to the dedicated product page, or contact us directly here - on 01327709439 or email ownlabel@bvwater.co.uk.
