Tanks/Vessels/Pipes

New Vessels

Conventionally, vessels are inspected prior to original hydrotest, but then not again until after an in-service period. This means that any defects that develop during the hydrotest of a new vessel may only be discovered after some period of service. This makes it difficult to determine whether they are manufacturing defects or service-induced defects. AE can eliminate this problem by monitoring the original hydrotest so that the vessel condition is known prior to putting it into service. AE monitoring of the hydrotest also provides a "fingerprint" for comparison with future AE tests.

Back to Top

Natural Gas Vehicle Cylinders

Back to Top

Railroad Tank Cars

The American Association of Railroads requires that all stub-sill railcars must undergo testing. This involves not only the vessels, but also the highly stressed areas of the chassis that are loaded during the test using jacks. The test detects cracking in the chassis or vessel and corrosion on insulated vessels without the need for costly insulation removal.

Back to Top

FRP Tanks/Pipes

Acoustic Emission testing is the most effective method of evaluating the structural integrity of FRP tanks and pipes. The AE test procedures, originally developed by SPI/CARP, are now written into ASTM and ASME codes. Testing involves attaching sensors to monitor the highly stressed areas while filling or pressurizing. AE may result from matrix crazing, debonding or fiber failure in the material.

Back to Top

Metal Pressure Vessels and Tanks

MONPAC^TM is an "expert system" for evaluating the condition of metal pressure vessels based on the experience from over 2000 tests. Monsanto developed the procedures that are now widely used in the oil and chemical industries. Benefits of this method are seen in the reduced inspection costs and reduced downtime resulting from improved information about plant condition. MONPAC is particularly effective on spheres, columns and for tank shell integrity but is also used on complete process systems. It gives a "color coding" for severity of emission, complete with associated recommendations. Testing is carried out by engineers and technicians trained and certified to meet our in-house qualifications for AE, Level II inspection.

Back to Top

Source Location

When two or more sensors detect an emission, it is possible to locate the source by using arrival times. Linear location is used on long gas cylinders and lines, planar location on thick-walled and gas-filled vessels and 3-D location on concrete structures.

Back to Top

Cool-down Monitoring

On certain types of thick-walled, high temperature vessels, the three-dimensional loading, resulting from cooldown, may be sufficient to stimulate defects to emit AE. In this case monitoring the cooldown provides information for scheduling further inspection and maintenance, resulting in considerable reduction of down- time.

Back to Top

Cold-shell Reactors

Reactors with refractory linings present a specific challenge for re-qualification because the removal of the lining to allow internal inspection is costly and can result in subsequent reliability problems. AE procedures for testing these vessels are used on-line or during pneumatic testing.

Back to Top

Above Ground Storage Tanks

 Back to Top

Valves

Losses due to internal valve leakage into the flare system in refineries can cost many hundreds of thousands of dollars per annum at an individual site. Physical Acoustics uses VPAC, a proprietary method for quantifying these leaks at individual valves so that appropriate maintenance decisions can be made.

Back to Top

Pipework

Back to Top

Coke Drums

Using AE testing, the integrity of a Coke Drum may be evaluated without taking the unit out of service. Such inspections are becoming a high priority for plant operations.

Back to Top

Pipelines

Back to Top