Plugged tapping points and impulse lines continue to be two of the greatest challenges within process instrumentation. While I have presented strategies on mitigating or detecting the conditions, when a plug occurs the plug needs to be cleaned. When a Best Practice of compact primary elements is not practical and Advanced Diagnostics have identified frequently plugged tapping points, the Autorodder from Clearguard is the New Technology that keeps your process online.
I have discussed a best practice of using compact primary elements for differential pressure (DP) flow measurement. The transmitter is mounted directly to the element with an integral flange. However, this is not always practical as the location of the measurement does not provide immediate access. In this situation a remote mount with impulse lines is more desirable.
Identifying plugged tapping points and impulse lines can be done through the use of Statistical Process Monitoring and Advanced Diagnostics. The mean and standard deviation of a process measurement is calculated. If either of the values start to drift, an alert is reported. Knowing there is a problem is only part of the solution. Maintenance is required to clear the blocked tapping point.
Plugged tapping points have historically been cleared by using a drill, or shoving an object in them. This is not a best practice for two reasons. First, cleaning a tapping point normally occurs only when the tapping point is completely plugged and the measurement can no longer be made. Prior to the tapping point becoming completely plugged, the operator cannot rely on the measurements received from the field instrument as he has no indication of how plugged the tapping point is. Secondly, the manual operation exposes a worker to the process fluid which can set up a dangerous situation. Thus, both reliability and safety have been compromised.
The Autorodder addresses both of these concerns. It works by periodically stroking a custom scraper through the tapping point. It is designed not to block the tapping point or impulse lines so the measurement can continuously be made. This allows the process to remain online. The Autorodder is also internal to your process piping. Hence, it does not expose a worker to a potentially hazardous situation. Reliability and safety remain intact at all times.
With all of the advances in process control and instrumentation reliability, there continue to be instances where maintenance is required. Again, best practices can mitigate a problem and advanced diagnostics can detect a problem. However, when there is a problem, you want a solution. The Autorodder is a great solution for your plugged tapping points and impulse lines.