Field Inspections
MONPAC

MISTRAS’ MONPAC system is an acoustic emission (AE) test designed to evaluate the structural integrity of metallic pressure vessels, spheres, columns, and tanks, enabling 100% inspection of a vessel during one pressure test.

MONPAC utilizes MISTRAS’ multi-channel acoustic emission (AE) systems and sensors that detect the high-frequency signals resulting from deterioration in structures when subjected to stress. These systems have sufficient speed and resolution to ensure real-time, on-screen indications of the development of any defects.

MONPAC is particularly effective on spheres and columns, and for tank shell integrity testing. It is also used for complete process systems and testing aerospace autoclaves.

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)

MONPAC Acoustic Emission Pressure Vessel Inspections

Using acoustic emission (AE) sensors to detect the high-frequency signals resulting from stress-related deterioration, MONPAC ensures real-time defect detection with high level speed and resolution, so even the smallest faults can be identified.

The signals may result from local over-stressed areas, crack growth, and/or corrosion products de-cohesion. According to evaluation criteria, developed after thousands of tests, MONPAC gives "color coding" for severity of emission and complete associated recommendations. The system will complete associated recommendations based on the determined severity of emission, all with the oversight and expertise of trained and certified AE technicians.

Corrosion, cracks, and other defects are common in areas of equipment that are frequently exposed to high levels of stress. When these defects accumulate, catastrophic damage can be caused, costing your facility valuable resources in asset repair and replacement. Acoustic emission testing can identify a long list of faults, including:

• Crack propagation
• Yielding
• Fatigue
• Corrosion
• Stress corrosion
• Creep
• Fiber fracture
• General deterioration

In order to detect these damages, pressure vessel owners and operators often take their assets out of service to internally inspect them. In one test conducted by an AE user group, over 95% of pressure vessels that were opened for conventional inspection did not require subsequent repair. MISTRAS' MONPAC technology package enables pressure vessel owners to keep their assets in service and more effectively plan maintenance activities to avoid lost productivity.

MONPAC Pressure Vessel Testing Benefits

MONPAC’s benefits method are largely seen in the reduced inspection costs and reduced downtime resulting from improved information about plant condition.

The method also provides a "color coding" for severity of emission, complete with associated recommendations.

Other MONPAC benefits include:

• Rapid inspection rates
• Global monitoring capabilities, including welds, repairs, and base metal
• In-service testing, including with product in vessel
• Minor insulation disturbances (insulation not removed, only few holes cut locally)
• Reduced inspection costs
• Reduced asset downtime

Test performed in accordance with ASME-Section V, Article 12