Monday, March 12, 2018

Water Main Inspection: Stopping Corrosion Before It Starts

ndt water main inspections

Water main inspection is an integral part of ensuring your pipelines are in working shape and best equipped to transport water safely. Without regular inspection, you run the risk of corrosion build-up causing significant and costly damage to your water main. Read on to learn how to prevent the headache of repairs!

What Causes Corrosion?

Corrosion can occur on the inside or outside of the pipe. Usually, the minerals in the drinking water precipitate on the inside of the pipe and protect it to some degree from corrosion pitting; however, the outside of the pipe is often in contact with the soil and the coal-tar coating applied by the factory breaks down in a short period of time. The minerals in the soil (including road salt) can attack the iron resulting in graphitic or pitting-type corrosion. When this advances to almost through-wall it can lead to two things:

  1. Failure of the pipeline is imminent
  2. Water quality will degrade because water inside the pipe is not always at a higher pressure than the water table outside the pipe, so dirty water can be drawn into the drinking water by high water table pressure or capillary effect.

If left un-repaired, it’s only a matter of time before the water main begins to suffer leaks or complete failure.

Not only can the appearance and smell of your water change (rust colored water, and a characteristic sediment scent are common), but the overall safety of your drinking water may suffer, leaving it undrinkable, or unsuitable for use.

Catching the First Signs of Wear

As with most kinds of damage, prevention is the best overall solution but once the pipeline is laid there is not a lot that can be done to prevent corrosion in the absence of a cathodic protection system. However; NDT (nondestructive testing) methods provided by industry leaders like PICA Corp allow you to detect corrosion at work long before it becomes a threat. Nondestructive testing, as the name suggests, inspects your pipelines without causing damage to them, and typically with minimal disruption to the pipeline service. Tools such as PICA’s HydraSnake are non-contact and equally sensitive to both external and internal wall-loss, giving you the full picture with ease.

Treating Corroded Water Mains

There are two ways of "treating" corroded sections of water main: either excavate to expose the main and clamp or replace a corroded section, or Hydrovac down to the main and install a zinc anode which will arrest the corrosion and stop it from getting any worse. Knowing where to dig to make the repairs, or anode placement, is where PICA comes in. We provide you with the "Good Information" so that you can make "Informed Decisions"

To learn more about getting your water mains tested, give us a call today!