Quality Risk Assessment for PPM & HVAC filter cleaning

This article contains Quality Risk Assessment for PPM and HVAC filter cleaning activity. Quality Risk Assessment (QRA) for risks associated with PPM & filter cleaning activity of HVAC system.  

Quality Risk Assessment for PPM and HVAC filter cleaning activity.

QRA for risks associated with PPM & HVAC filter cleaning activity.

OBJECTIVE:

This quality risk assessment (QRA) is prepared to identify, assess & mitigate the potential risks associated with PPM & HVAC filter cleaning activity.

BACKGROUND :

• As per current practices, complete cleaning of area is performed after carrying out PPM (preventive maintenance) of HVAC (heating, ventilating and air conditioning) system. The PPM activity is performed by engineering associate in service floor. As per HVAC design, there is terminal HEPA (High efficiency particulate air) filters inside the production room and air coming inside the room is passed through terminal HEPA filters.
• These terminal HEPA filters are not disturbed during PPM activity so as to maintain the quality of air delivered into production room. Hence complete cleaning of area may not be required after PPM of HVAC system.
• Based on the above fact, this QRA is prepared to identify, assess & mitigate the potential risks associated with PPM & filter cleaning activity of HVAC system.

SCOPE:

This QRA is applicable to HVAC system

IDENTIFICATION OF TEAM:

APPROACH FOR QRA:

• Sop Management of Quality Risk Assessment was followed for conducting risk assessment. This quality risk assessment document shall focus but not limited to following aspects;
• Brief description of HVAC system
• PPM (preventive maintenance) & filter cleaning procedure of HVAC system
• Details of assessment:
• Identification of potential failure effects & causes of PPM/ filter cleaning activity of HVAC system
• Assessment and evaluation of all potential causes based on existing controls
• Risk mitigation strategy/ CAPA (as applicable)

Risk assessment/ management used: FMEA (Failure Mode Effect Analysis)

Brief description of HVAC system:

• The fresh air (10%) is taken from atmosphere & filtered through EU4 (10 micron) filter. The air is passed through cooling coil in TFA (Treated fresh air) unit to remove the moisture. The moisture in air is trapped by mist eliminator.
• This pre-treated fresh air (10%) and return air (90%) is passed through AHU (Air Handling Unit) where air is filtered through EU7 (3micron) filter. Then some air passes through bypass damper and some cooled by cooling coil for removing moisture as per design.
• The cool air is further sucked by centrifugal blower and blow through third stage fine filtration EU9 ( 0.3 micron) with 50 % efficiency. Excess air is purge to atmosphere through HEPA EU-13 (0.3 micron).
• This cooled and filtered air is passed through heaters for maintaining the required temperature. Further, air is passed through supply air duct and finally passed through EU13 filter (0.3micron) also called terminal HEPA (High efficiency particulate air) having 99.97% efficiency.
• The air from production room is returned through return air riser, with filtration EU3 (20micron) filter to AHU for recirculation. For low RH (Relative Humidity) less than 45%, 30%, 15% room return air is passed through dehumidifier unit, where silica desiccant rotor bed is used for removing the moisture from air. This bed is recharged by reactivation air for removing moisture again. This dehumidifier air passes through AHU system process then in the room.

PPM (preventive maintenance) & filter cleaning procedure of HVAC system:

• PPM (preventive maintenance) procedure of HVAC system:

• Preventive maintenance of HVAC system is carried out as per SOP preventive maintenance management system and SOP for HVAC filters management is followed for cleaning the HVAC filters. Refer below process for carrying out PPM activity:
  • SAP Operator: SAP work permit for planned activity are issued & distributed to section in charge
  • Engineering: Section in charge assigns the work order to relevant associate
  • Engineering: Initiation of work permit by associate for carrying out planned activity
  • Area Owner: Release of HVAC system/ production room for carrying out planned activity
  • Engineering: Execution of planned activity by engineering associate
  • Quality Assurance: Assessment of executed planned activity & release of HVAC system
  • Area Owner/User: Taken over of HVAC system/ production room from engineering
  • The spare set of filters are used during filter cleaning of HVAC filters. Also, below key functions are checked during PPM of HVAC system;

Mechanical Operations:

1. 1. 1. Check the physical condition of blower.
      2. Check condition of Motor.
      3. Clean the blower and motor.
      4. Check the conditions of belts for cracks, wear & tare, torn, loosens by using torch if found damaged replace the belts.
      5. Check condition of Blower pulley as applicable.
      6. Check condition of motor pulley as applicable.
      7. Check alignment of Motor pulley & blower.
      8. Check for any abnormality in blower like vibration, and noise, rectify if any problem.
      9. Check for any abnormality in motor like vibration, overheating and noise, rectify if any problem.
      10. Clean the Pre-Cooling unit
      11. Clean the main-Cooling coil
      12. Clean Condensate drain tray and U trap line.
      13. Check filter condition for any major media torn, frame damage, gasket damage and rectify or replace the same as applicable.
      14. Clean the AHU cabinet internal surface.
      15. Check for the operation of all volume control dampers.
      16. Check the condition of megnahelic gauge tubing.
      17. Check for leakages through AHU door and section gaps.
      18. Check the AHU door gasket.

Electrical Operations:

1. 1. 1. Check for the proper functioning of Heater(s), wherever applicable.
      2. Check the door interlocking with blower and inspection lamp
      3. Clean AHU Electrical Panel.
      4. Clean Filter of AHU Electrical Panel.
      5. Tight all cable connections.
      6. Check earthing connection and continuity, rectify if problem.
      7. Check all selector switch operation
      8. Check tower indication lamp for proper operation.
      9. Check tripping signal indication of AHU.
      10. Check the operation of pressure switch for tripping of blower and heaters supply, as applicable.
      11. Check fire damper operation
      12. Check heaters power switch working
      13. Check 3way valve operation.
      14. Check 3way valve leakage.
      15. Start the system and check functionality of all instruments.

Mechanical & Electrical Operations of dehumidifier:

1. 1. 1. Clean the reactivation & process air flow filters.
      2. Clean the internal cabinet surface.
      3. Clean the desiccant rotor by low pressure compressed air.
      4. Check the operation of pneumatic or steam actuator valve.
      5. Check the rotor drive mechanism for alignment, tension & condition.
      6. Check the condition of Desiccant Rotor, if damage than replace it.
      7. Check the condition rotor shaft bearing.
      8. Check condition of rotor seal.
      9. Check & tight the all bolts & screws.
      10. Check the heater condition.
      11. Check the process & reaction blower & motor for any abnormal noise & vibration.
      12. Check the leakages from ducting.
      13. Check the leakages from chilled water line.
      14. Check the leakages from steam line & steam coil.
      15. Check the operation of steam valve, trap and strainer.
      16. Check the operation of all dampers.
      17. Check the condition of moving part.
      18. Check the air flow switch.
      19. Check the condition of insulation for piping & ducting.
      20. Check the painting condition of system.
      21. Check condition of the identification labels fixed on system.
      22. Check the working safety of thermostat for heater.
      23. Check the safety interlocks of system.
      24. Check the inspection lamp working.
      25. Check the earthing of system.

The above mentioned activities during PPM of HVAC system are executed in service floor only. It is also identified that terminal HEPA filters are not disturbed during preventive maintenance.

DETAILS OF ASSESSMENT:

• Risk analysis: FMEA (Failure Mode Effect Analysis) is used as a risk management tool

CORRECTIVE AND PREVENTIVE ACTIONS:

• Sufficient controls are available to mitigate the risk hence no further CAPA are proposed.

 CONCLUSION:

• Quality risk assessment for risks associated with PPM & filter cleaning activity of HVAC system is performed.
• The procedure for performing PPM and filter cleaning activity has been reviewed. The potential risk associated with PPM and filter cleaning activity were identified & risk assessment was carried out.
• Based on the risk assessment, there is no possibility of introduction of dust particles from AHU to production rooms during PPM and filter cleaning activity. Hence the cleanliness of production room is not compromised under such conditions.
• Moreover, no production activities are carried out during PPM/ filter cleaning activities. Also, the process conditions (temperature, RH and DP) are monitored & ensured before start of process activities.
• Based on the above discussion, there is no impact the room cleanliness so complete cleaning of room after carrying out the PPM/ filter cleaning activity is not required.

APPROVAL: