Purpose
To describe the
procedure for cleaning and replacement of filters.
Procedure:
- Switch off the power supply of the machine.
- Put up board “Man at work, do not switch ON”.
- Open the door of the machine and removes the filters from filter housing.
- Keep the dusty filters in a Poly-bag.
- Take the dusty filter in designated filter cleaning area.
- Take out the filter from poly-bag and wash it with Purified water and then with air. Water Pressure should not be more than 2.0 kg/cm2.
- After washing the filter, remove its water by applying air in opposite direction and keep it on the racks for complete drying. Air Pressure should not be more than 2.0 kg/cm2.
- Check for any damage of filter physically and if filter found damage, change it with a new filter.
- Cover the clean filter in a poly-bag.
- Clean the filter housing with vacuum cleaner and duster.
- Fit the filter in its place and ensure that there should be no gap around filter and filter housing.
- Cleaning of Return riser filters and RLAF filters (pre & fine filters) are in concerned department scope.
- If any filter found damage concerned department will raise a work order to replace damage filter as per SOP Break down maintenance procedure
- Cleaning activities of all filters will be carried out as per Annual Master Filter Cleaning
- All concerned shall record all activity of cleaning and replacement record
- After cleaning of riser filter update the status of cleaning on label as per QA SOP of Procedure for status labelling
Frequency of Cleaning of Filters
Pre-Filter Weekly±2
Days or DP indication
Pre-Filter Weekly±2
Days or DP indication
Fresh Air
filter Weekly±2
Days
Fine
Filter 15
±2 Days or DP indication
RLAF Pre
filter Weekly±2
Days/ DP Alarming or during product change over
RLAF Fine
filter 15±2
Days or DP Alarming
Return Riser Filter Weekly±2 Days
or during product change over
Frequency of
Replacement of Filters
Fresh Air
Filter After
every 2 years ± 15 days
Pre-filter
(5 µ) After
every 2 years ± 15 days
Fine filter
(3 µ) After
every 2 years ± 15 days
HEPA Filter
(0.3 µ) After
every 4 years ± 15 days
(Note: - if any
filter found damaged it can be replaced immediately)
Repairing and
Replacement of HEPA Filters:
If side leakages
are observed between filter and housing, then replace the gasket and seal the
gap with silicon sealant.
Acceptance Limit: During filter integrity if the downstream
leakage exceeds 0.01 % from the gasket, change the gasket. After rectification
of the leakage if the leakage does not fall within 0.01 %, replace the HEPA
filter with new one.
- If HEPA filter need to replace, switch off the AHU, close the supply damper, close the fresh air damper and open the HEPA filter from filter housing. Clean the housing area and put the new HEPA filter in housing. Fill silicon sealant in the edges and corners of filter housing and terminal box and tight all the bolts. Check the HEPA filter integrity and if the filter passes in integrity, open the supply and fresh air damper. Run the system for at least 30 minutes. Check the particle count in respective area. If particle count of area is under limit of respective class, then hand over the area for Fumigation and Microbial Count Test.
