Technical Bulletin # P-04
An Introduction To Ultrasonic Pipe
Testing
Through A Free Pipe Sample Analysis
THE PROBLEM:
While most building operators have
established very well defined preventative maintenance schedules and testing
programs for their many mechanical and electrical services, few sufficiently
monitor the condition of their HVAC piping systems to ensure reliable and long
service life operation.
One reason is due to the hidden nature of
most corrosion problems, and the fact that metal piping is continuously
dissolved and flushed away. The obvious difficulties associated with physically
removing pipe samples for metallurgical analysis, the most common form of
advanced pipe testing, is another good reason why attention to this critically
important area of operations is so often neglected.
Corrosion coupons, the most relied upon
form of corrosion testing with the building management industry, provide some
insight into chemical treatment effectiveness, but fall far short of providing
either accurate wall loss data, or corrosion information relative to the entire
piping system. Read more about the
various limitations of corrosion coupons in our Technical Bulletin #
C-01.
THE SOLUTION:
Highly accurate monitoring of interior
pipe corrosion can be easily achieved without any service disruption and at
reasonable expense through the application of ultrasonic technology and the
appropriate analysis techniques.
Ultrasound is the process by which ultra
high frequency sound waves are introduced into a material from the outer wall
surface. The sound travels through the metal, and upon reaching the interior
wall, reflects back toward its source in the form of an echo. An integral
receiver captures the echo, and by calculating the time of travel, displays the
precise wall thickness. Typical accuracy of ultrasound based measurement,
assuming proper application, calibration, and material composition, is 0.001
inches.
Through specialized computer analysis, we
can evaluate this basic data to provide even further information about the
subject pipe such as:
- Pipe Metal Loss
- Corrosion Rate
- Percentage Of Allowable Loss
- Remaining Pipe Life
- Retirement Date
- Pass/Fail Recommendation
With our ultrasonic fixed point testing
program, we can apply a permanent sensor template to the pipe, and thereby
regularly measure the loss of actual pipe metal to provide a continuing record
of true corrosion rate. See Technical Bulletin
# C-01 about fixed point ultrasonic pipe testing. A far more
detailed explanation of our template testing and reporting procedures can be
found under the heading
Testing Services -
Advanced Corrosion Monitoring at the Testing Services
menu.
Our single location free sample report,
offered here, provides the same level of information found in our full report,
and offers potential clients the opportunity to review our pipe testing program
using their own information. A total of 12 individual ultrasonic wall thickness
measurements are recorded for the sample, initial pipe wall thickness is
identified, and the minimum acceptable wall thickness calculated. Various
projections based upon the average of all 12 measurements as well as the
minimum measurement are presented.
A far more detailed explanation of our
testing and reporting procedures can be found under the heading
Testing Services -
Ultrasonic Pipe Testing at the Testing Services menu.
To receive the above analysis along with
our critique on a section of your own building piping, simply return to us a
completed analysis questionnaire along with any sample of piping approximately
6" in length. Please mail your sample to our street address provided on the
questionnaire, not our box number. Circular cutout sections of pipe wall are
also suitable for testing. If no removed samples of pipe exist, please contact
our office for other possible arrangements.
Testing
Services