Acoustic Emission Pressure Vessel Testing (MONPAC)

 

MONPAC is an Acoustic Emission based expert system for evaluating the structural integrity of metallic pressure vessels, spheres, columns and tanks. MONPAC consists of AE test procedures and evaluation criteria and enables 100% inspection of the vessel during one pressure test. MONPAC can be applied during:

• First Hydrotest of a new Pressure Vessel according to ASME-V Part 12

• Requalification Hydrotest of a used Pressure Vessel

• On Line Pressurization (in-service with working fluid)

3D View of sphere with Acoustic Emission
MONPAC grades and zone radius shown.

 

The method utilizes PAC's Multichannel Acoustic Emission Systems and Sensors which detect the high-frequency signals resulting from deterioration in the structure when subject to stress. The systems have sufficient speed and resolution to ensure real-time, on-sreen indications of the development of any defects.

The signals may result from local over-stressed areas, crack growth, corrosion products de-cohesion. According to evaluation criteria, which were developed after thousands of tests, MONPAC gives 'color coding' for severity of emission and complete associated recommendations.

 

 

Advantages

• Rapid inspection (e.g. a 15m sphere is tested in approx. 3 days).

• Global monitoring (100% inspection, including welds, repairs, base metal etc.)

• On-line testing (can be tested with service product).

• Minor disturbance of insulation (insulation not removed, only few holes are cut locally).

• Reduction in inspection costs.

• Reduction in downtime resulting from improved information about plant condition.

• The Acoustic Emission test is performed in accordance with ASME - Section V, Article 12.

 

Drag mouse over the colored areas to see Acoustic Emission - MONPAC grading detail

 

Benefits of the method are largely seen in the reduced inspection costs and reduced downtime resulting from improved information about plant condition.  MONPAC is particularly effective on spheres and columns, and for tank shell integrity testing.  It is also used on complete process systems.  The method provides a "color coding" for severity of emission, complete with associated recommendations.