Q: What types of pipes can be assessed with  TPATM?
A: TPATM can assess the condition of the following  types of watermains provided they are pressurized to at least 5 psig / 35 kPa / 0.35 bar:

Cast Iron (CI)
up to DN 600
Stainless Steel
up to DN 450, leak detection up to DN 600
Spun Iron (SI)
up to DN 600
Ductile Iron (DI)
up to DN 600
Asbestos Cement (AC)
up to DN 450, leak detection up to DN 600
Acrylonitrile butadiene styrene (ABS)
up to DN 280
Polyethylene (PE)
up to DN 280/315 depending on SDR
Polyvinyl chloride (PVC)
up to DN 280/315 depending on SDR
Prestressed concrete cylinder pipe (PCCP)
Leak Detection Only

Larger diameter and heavily insulated  pipes can be inspected using the TPA+ system which uses and in-pipe sound source. Both  TPATM  and TPA+ systems can be used to inspect sewage force-mains, insulated steam, hot water and chilled water pipes of comparable diameter.

Q: How long a section of pipe can be inspected at one time?
A: For ferrous and asbestos cement pipes, up to 500 m, but we recommend distances of 100-200 m for optimum accuracy.  For plastic pipes, 150 m or less is best for condition assessment, although leak detection is possible at longer distances.  A two to three person crew can typically inspect between 1.2 and 1.8  km per day.

Q: How short a section of pipe can be inspected at one time?
A: 10 m, however, 25 m is recommended for better accuracy, particularly for wall thickness measurements.

Q: What type of sensors does TPATM use?
A: Ceramic-shear accelerometers with a sensitivity of at least 10,000 mV/g for standard applications with higher sensitivity units used for some pipe material/diameter combinations. Hydrophones can also be used for certain specialty applications.

Q: Does TPATM use ultrasound?
A: No.  TPA’s sound sources generate low frequency tones under 5,000 Hz.

Q: Is TPATM really “non-invasive”
A: Yes. In its standard configuration no instruments are inserted into the water stream.

Q: Does TPATM generate a water hammer or large pressure transient that could potentially a pipe or loosen sediment?
A: No.  TPA’s sound sources generate small pressure disturbances, that although detectable by very sensitive instruments, have virtually no impact on overall pipe operating pressures.

Q: How accurate is TPATM‘s leak detection?
A: Field tests of simulated leaks have shown the ability to detect leaks of well under under 3 L/min at distances of at least 200 m.  Nominal leak detection accuracy for ferrous pipes is ±2 pipe diameters 9 times out of 10 for measurement distances under 350 m with a false positive rate ranging from 1 in 40 to 1 in 50 depending on pipe diameter and background noise levels.

Q: What type of pipe-wall condition information does TPATM provide?
A: Average pipe-wall all acoustic impedance, thickness, and stiffness are the primary data outputs, and are typically accurate within +/-5% to +/-15% of  destructively tested values for a given 10-15 m section of pipe. The locations of sudden changes in wall properties, pipe section joints, obstructions and leaks are also provided.  Pipe wall deflection, hoop stresses, remaining service life and levels of tuberculation can also be estimated.

Q: What are the components of the TPATM  system?
A:

A: Accelerometers or hydrophones with variable-gain B: Multi-channel transceivers for data acquisition*
C: Data display and storage D: Impulse hammer with force sensor
E: Thermodilatohydrometer F: Variable-frequency hydro-dynamic sound source**
G: Telescoping guide tube for sensor placement H: Valve key

*Wired links can be substituted for use in enclosed spaces.

**Where the use of a hydro-acoustic sound source is not possible or where maximum accuracy is required, then the in-pipe TPA+ sonar array is be used.

Q: How can I learn more about how TPATM can help me better manage my buried assets?
A: Contact us at assessment@iconac.co.