Langelier Index (Pipe Corrosion)


Langelier Index (Pipe Corrosion)

The tests carried out for a Langelier Index are as follows:

  • pH
  • Total Dissolved Solids
  • Total Alkalinity
  • Calcium Hardness
The Langelier Index is an approximate indicator of the degree of saturation of calcium carbonate in water.
  • If the Langelier Index is negative, then the water is under saturated with calcium carbonate and will tend to be corrosive in the distribution system.
  • If the Langelier Index is positive, then the water is over saturated with calcium carbonate and will tend to deposit calcium carbonate forming scales in the distribution system.
  • If the Langelier Index is close to zero, then the water is just saturated with calcium carbonate and will neither be strongly corrosive or scale forming.

The Langelier Index is one of several tools used by water filter companies for stabilizing water to control both internal corrosion and the deposition of scale. Water filter companies can optimize water supply systems and identify leakage potentials with the Langelier Index.

Experience has shown that Langelier Index in the range of -1 to +1 has a relatively low corrosion impact on metallic components of the distribution system. Langelier Index values outside this range may result in laundry stains or leaks.

Highly Aggressive < -2.0
Moderately Aggressive -2.0 to 0.0
Non Aggressive > 0.0

Sample generally should be taken from the HOT WATER TAP.  Temperature should be noted from thermostat by sampler when taking the sample and noted on the Chain of Custody for the testing laboratory. Turnaround time on results is 10 working days.

The simple kit contains one 250ml plastic bottle and instructions on how to take your water sample properly. Once the sample is taken, post or deliver the bottles back to us on the same day.

A Certificate of Analysis will be sent to you with your water test results along with an information sheet on understanding your results.