TIPS & TOOLS:  Mechanical Integrity

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Mechanical Integrity is a critical part of any PSM program.  With the increased focus of OSHA on ammonia plants, it is even becoming more important.

 A five year Mechanical Integrity Audit consists of various tests on the system. It is important to have trained technicians and specialized tools to complete the inspection. To perform this work requires different types of people with their own specialized skills.

Mechanical Integrity Audits consist of detailed inspection reports that will highlight all of the issues found, items requiring more work and items that require immediate repair.

Mechanical Integrity Audits consists of the following:

• Review the PNA and SOPS
• Review records to see if PSM is being followed
• Vibration analysis on all Compressors
• Oil Analysis on all Compressors
• IIAR 109 on all equipment. Update as required
• Ammonia Sample taken on system
• Photos and documentation on all potential issues in the plant that were generated from the IIAR 109 inspections
• Non-destructive testing of pipe and vessels

This is a typical list to be done on the following equipment by qualified personal:

Compressors

• Fill out IIAR-109 Form
• Verify compressor end play is within manufacturer specifications
• Check torque on coupling bolts
• Check and test all safeties to include suction, discharge, oil pressure and temperature cutouts
• Check Compressor alignment
• Check for noise and vibrations
• Perform vibration analysis
• Check calibration of all pressure transducers and temp probes
• Perform oil analysis of compressors

Vessels

• Check and calibrate of level controls 
• Fill out IIAR -109 Form

Evaporators/Air units

• Perform detailed external inspection - units and valves
• Inspect fans and motor per proper operation  evaps Fill out IIAR 109 forms

Condensers

• Fill out IIAR -109 Form
• Inspect condenser spray nozzles
• Inspect fans, motors and pumps for proper operation
• Check the water sump Inspect tube bundle, fans and shafts
• Inspect all operating and safety controls – calibrate
• Perform a IIAR 109 inspection on purger

Sensing Devices

• Test and calibrate ammonia sensors
• Check calibration - temperature sensors storage areas
• Test and calibrate main system pressure transducers - low side, intermediate and discharge

Other items to check on a typical system

• Visually inspect condition of all exposed piping and vessels
• Visually inspect condition of all insulation for problems
• Visually inspect all valve for rust or leak potential
• Take sample of refrigerant Ammonia
• Verify that all pipe hangers and supports are intact
• Provide written report of inspection and deficiencies to address