One of the most important and efficient technolgies to test the pressure in service condition is the Acoustic Emission

Burring and insulate the vessels is a technique which creates the problem of the control of the defects which may be originated and propagated during the works.
Being sure which probable mechanical defects will be surveyed during the manufacturer control and in any case during the hydraulic test, it remains only the problem of the individuation of defects originated and advanced after the hydraulic test.

These kind of defects are due to:
-       Stress corrosion
-       Hydrogen embrittlement
-       Corrosion-Fatigue

All these defects results from the presence of particular chemical- physical condition and evolve only whether such conditions exist.
Thereby it is necessary to make the tests in services conditions to detect them. The preferable technique for this kind of test is the Acoustic Emission  based on surveying of the microscopical waves of deformation emitted into the material when the cracks go on.
The Acoustic Emission Monitoring consists in the installation of some sensors on the vessel surface connected by cable to a reader device.
The signals are transmitted on an electronic replaceable memory and periodically transferred to a computer to elaborate them and in case individuate whether the defects go on.
M.I.T. Company may furnish devices, software, the service of pick data up and the preparation of a report.