To enhance corrosion control, ethylene glycol or propylene glycol solutions must remain alkaline. The addition of a pH buffer is required to neutralize the acids formed from glycol degradation that will occur over time. Significant air ingress and/or the acidic by-products of glycol degradation will lower the pH value, and as the pH value decreases, the rate of glycol degradation will accelerate.
To prevent this condition, the buffering capacity is routinely monitored and measured in terms of Reserve Alkalinity. The Reserve Alkalinity of a propylene glycol or ethylene glycol based system, is a measure of the neutralizing capability and it will vary depending on the type and quantity of additives used in a particular type of glycol. Maintain the recommended Reserve Alkalinity in your solutions with supplemental additions of a suitable buffer. In systems where there is significant air ingress, choose Buffer B600. For systems with no significant air ingress, choose Buffer B601.