SOP for Integrity testing Of HEPA filters

This Document describes (Standard Operating procedure) SOP for Integrity testing Of HEPA filters

Table of Contents

The Purpose of this SOP is to lay down the procedure for Integrity testing Of HEPA filters.
This procedure is applicable to all Engineering Department for Integrity testing Of HEPA filters.

All Engineering personnel’s shall be responsible to follow and implement this SOP.

Start AHU of which Integrity testing Of HEPA filters checking is to be verified.
Ensure the power supply of photometer is’ ON’
Start the compressed air or N2 gas to generate the test aerosol at minimum pressure 20 psi.
Direct the test aerosol at the return air point of fresh air intake of the AHU.
Put the photometer selector switch ‘ON’ upstream mode.
Connect the tube of photometer to the stream port of HEPA housing.
If the upstream port is not provided then check upstream concentration at main supply duct of AHU.
Wait until the photometer reading crosses the 22% reading then set this reading as 100% concentration, using the internal calibration button.
Put the photometer selector switch on downstream mode.
Wait until photometer displays ‘0’ (zero).
Measure the downstream concentration by holding the probe approximately one inch away from face of the filter.
Scan the corners of HEPA filter for checking the installation leakages.
If the leakage is more than 0.01% of upstream aerosol concentration, rectify the leakage by tightening the locking bolts.
Scan the entire filter face including perimeters with the probe of photometer in overlapping strokes, traversing at approximately 10 feet per minute ( FPM ).
Replace the filter and check the integrity of filter as per above points

Start the LAF of which Integrity testing Of HEPA filters is to be checked.
Record the magnehelic gauge reading.
Ensure the power supply of photometer is’ ON’.
Start the compressed air to generate the test aerosol at minimum pressure 20 psi.
Direct the test aerosol at the return air point of fresh air intake of the AHU.
Put the photometer selector switch ‘ON’ upstream mode.
Wait until the photometer reading crosses the 22% reading then set this reading as 100% concentration, using the internal calibration button.
Put the photometer selector switch on downstream mode.
Wait until photometer displays ‘0’ (zero).
Measure the downstream concentration by holding the probe approximately one inch away from face of the filter.
Scan the corners of HEPA filter for checking the installation leakages.
If the leakage is more than 0.01% of upstream aerosol concentration, rectify the leakage by tightening the locking bolts.
Scan the entire filter face including perimeters with the probe of photometer in overlapping strokes ,traversing at approximately 10 feet per minute ( FPM ).
Replace the filter and check the integrity of filter as per above points.

Start AHU of which Integrity testing Of HEPA filters checking is to be checked.
Ensure the power supply of photometer is’ ON’.
Start the compressed air to generate the test aerosol at minimum pressure 20 psi.
Direct the test aerosol at the return air point of fresh air intake of the AHU.
Put the photometer selector switch ‘ON’ upstream mode.
Check the upstream concentration of PAO before HEPA filters at AHU/Plenum Wait until the photometer displays 100% upstream concentration.
Remove the tube of photometer and seal the AHU/Plenum port and ensure to zero leakage through port.
Before entering AHU/Plenum he / her should wear apron, mask.
Put the photometer selector switch on downstream mode.
Wait until photometer displays ‘0’ (zero).
Open the AHU/Plenum door and enter inside.
Measure the downstream concentration by holding the probe approximately one inch away from face of the filter.
Scan the corners of HEPA filter for checking the installation leakages.
If the leakage is more than 0.01% of upstream aerosol concentration, rectify the leakage by tightening the locking bolts.
Scan the entire filter face including perimeters with the probe of photometer in Overlapping strokes, traversing at approximately 10 feet per minute (FPM).
Replace the filter and check the integrity of filter as per above points

HVAC system– Yearly ± 30 days and LAF system- Six Monthly ± 15 days.