Voltage Setting for Powercrete Inspection
Testing a pipeline coating for holidays is one of many incredibly critical steps in the process of building a pipeline. Small coating defects can often quickly become large drains on CP systems or large corrosion problems. Being certain that you are burying good coating is imperative.
So what should the setting be when holiday detecting Powercrete products? The general rule is 125 volts per mil of coating. This would be the guideline for Powercrete J, Powercrete R65/F1 or Powercrete R95. So, if the coating spec says the the Powercrete coating thickiness should be a minimum of 40 mils; you could set your holiday tester to 5 Kv. You must be careful though!
If your Powercrete R95 is 40 mils thick; but your adjacent FBE coating is only 18 mils thick; then your holiday detector is going to cause immediate damage to that adjacent factory applied coating as soon as the holiday detector leaves the Powercrete and gets over the top of the FBE.