SOP For Preventive Maintenance of Lyophilizer EN-53

The purpose of this (Standard Operating Procedure) SOP For Preventive Maintenance of Lyophilizer is to provide guidelines and instructions for the preventive maintenance of the Lyophilizer to ensure its optimal performance, reliability, and compliance with product quality and safety standards.SOP For Preventive Maintenance of Lyophilizer

SOP For Preventive Maintenance of Lyophilizer

    • To lay down the preventive maintenance procedure of Lyophilizer.
  • SCOPE:
    • This SOP is applicable for preventive maintenance of Lyophilizer Machine installed in the production department .
    • Technician/ Operator shall be responsible for proper execution of preventive maintenance as per SOP.
    • Engineering – Head shall be responsible for reviewing the SOP and for ensuring proper execution of preventive maintenance.
    • Engineering – Head shall be accountable for proper implementation of the SOP.
    • Preventive Maintenance: The preventive maintenance describes all scheduled work done on a routine, predefined basis to maintain facilities, equipment, utilities and devices in good status in order to ensure reliable performance.
    • Preventive maintenance shall be executed as per the SOP No.: SOP/ENXXXYYY – Execution of Preventive Maintenance.
    • Ensure that the spare parts are available at the time of preventive maintenance.
  • Monthly Check list for preventive maintenance:
    • Check the oil level in the vacuum pumps, if not full top it.
    • Check for refrigerant standing pressure; it should not below the recommended value.
    • Check for compressor sight glass for oil level; if the oil level is below recommended level then top up the level.
    • Check for level in the expansion tank; if it is below recommended level then top up the level.
    • Check for Hydraulic tank oil level; if it is below recommended level then top up the level.
    • Check by visual inspection for any leakages around the unit, if found rectify the same.
    • Change the vacuum pump oil at every 250 running hours.
    • Checking of diaphragm valves and gaskets
    • Replace all the Chamber/condenser drain line flange gaskets.
    • Check all sanitary gaskets, if required then change.
    • Check the product chamber gaskets, if required then change.
    • Check the condenser chamber gaskets, if required then change.
    • All silicon gaskets Shall be replaced after every three months.
  • Half Yearly Check list for preventive maintenance:
    • Carry out the entire monthly check list.
    • Ensure calibration of all installed instruments and sensor.
    • Check for heater amps.
    • Check for all compressor amps.
    • Check for water pumps amps.
    • Check for all vacuum pump amps.
    • Check for hydraulic pump amps.
    • Check oil leakage inside the bellow.
    • Check the alignment of loading and unloading conveyor belts with the loading station of the lyophilizer.
  • Yearly Check list for preventive maintenance:
    • Carry out the entire half yearly check list.
    • Check the condition of insulation; if required insulates the same.
    • Check and if required then replace the product chamber gaskets.
    • Check for any loose connection in main and control panel, if required tighten the same.
    • De-scaling and flushing the water condenser.
    • Back up SQL audit trial master file.
    • Backup historian IHA files.
    • Backup crystal report folder.
    • Check the condition of refrigeration filter, if required then change.
    • Check the condition of compressor oil, if required then change.
    • Check and replace the insulation, if required then change.
    • Check the frame for corrosion spot, if required paint the frame suitable paint.
    • Check for safety valve operation for proper functioning.
    • Check and replace the PLC battery, if required.
    • Carry out vacuum pump maintenance, if required.
    • Carry out hydraulic cylinder maintenance, if required.
    • Check compressor suction and discharge valve plates, replace if required.
  • Maintenance Procedure
  • Calibration of sensor test
    • Remove the sensor from the location.
    • Place the sensor tip in the cooling appliances or ice bath along with the calibrated digital thermometer at simulated temperatures.
    • Observe the temperature on the MMI and digital thermometer and record the readings.
    • If the readings are not within limits, check the sensor and if required replace the temperature sensor with new one and follow the same procedure.
    • Some instruments that can be calibrated only at the time of gas fill as per SOP/EN/XXXYYY.
  • Checking, cleaning and Replacement of filter drier core
    • The frequency of replacement of filter drier core shall be done as per needed for following reasons
    • When there is sufficient discharge but no suction.
    • By any reason compressor oil got pumped in to system.
    • If filter choke
    • Check the filter drier core for the choking; the filter replacement procedure is as follows.
    • Close the valve 411 and 411A.
    • Releases the refrigerant through pin valve.
    • Open all the 8 bolts.
    • Remove the old cartridge. Check and clean the cartridge.
    • If required replace with new one along with the new gaskets.
    • Properly tighten all the bolts.
    • Vacuum the filter dryer through pin valve for 5 minutes.
    • Close the pin valve
    • Open the valve 411 and 411A.
    • If the values are not proper, replace the thermocouple input module or contact the Service person for the further details.
    • Restore the connection as per original.
  • Compressor oil change procedure
    • Recommended oil  to be used  – Emkarate RL 32H
    • Check the oil level in oil chamber, when the oil level goes down, when tripping on oil pressure control, when oil filter choke, then oil has to be replaced.
    • The oil replacement procedure as follows.
    • Close the valve 402 and 406.
    • Remove the dummy nut from oil charge port installed in the charging line.
    • Bleed the available refrigerant.
    • Remove the charging line.
    • Vacuum the compressor through the pin valve available valve on 427.
    • Install the charging line on oil charging port with other end in the oil tin.
    • Charge the oil as per the quantity required. Charge the fresh oil +500 ml to the removed quantity.
    • Remove the vacuum.
    • Remove the charging line and fix back the dummy nut.
    • Open valve 402 and 406
    • Checking of the oil filter shall be after every three month.
  • Hydraulic system and stoppering pressure adjustment
    • Recommended oil to be used Hydrol -68
    • The maintenance activity is required for the following reasons
    • Pressure to be decreased in case the vials are getting broken during stoppering.
    • Pressure to be increased if all the vials are not getting stoppered properly.
    • Precautions to be taken before adjusting the pressure – See that the chamber door is closed; use the proper size allen key; the oil in hydraulic system reservoir is as per the requirement.
    • Enter in maintenance mode on SCADA.
    • Switch on the hydraulic motor.
    • Switch on the UP solenoid.
    • Wait till the hydraulic moved totally upwards and pressure stabilizes.
    • Turn the allen key clockwise to increase the pressure and anti clockwise to decrease the pressure.
    • Switch on down solenoid and after cylinder goes to full down position stop all the outputs.
    • The checking of hydraulic system shall be made after every month.
  • Vacuum pump oil change procedure
    • Recommended oil to be used N62 or HE 200 Oil
    • The oil change frequency will be as if the vacuum pump running hours exceeds by 250 hrs.
    • If the vacuum pump goes dirty, then replace the oil.
    • If any water enters in to vacuum pump oil then change the vacuum pump oil.
    • Switch off the main power off before changing the vacuum pump oil.
    • Drain the oil through drain port.
    • Fill the oil through fill port and drain and flush.
    • Fill up to 60 % level.
    • Checking and changing of vacuum pump oil shall be done after every 250 hrs.
  • Bellows oil leakage check procedure
    • The bellows oil leakage check procedure shall after at every six months or whenever the hydraulic cylinder shaft seal fail.
    • Take the hydraulic cylinder to down position and switch off the main power to hydraulic motor.
    • Remove the bolts and lift the seal slowly and inspect for any oil leakage.
    • If the oil quantity is more than approximately 100 ml check for hydraulic cylinders shaft seal and replace the same.
  •  Checking of solenoid valves
    • Solenoid valve will required maintenance if the coil blows off, and / or if we lose continuity between two wires.
    • Check the solenoid valve for connector’s connection properly.
    • Remove the dust from ports.
    • Remove and clean the connector.
    • To remove and replacement of solenoid coil, Insert two small screw drivers below the coil and gently press upwards to remove the coil.
    • Install the new coil and replace the connector back.
    • Checking of solenoid valve shall be on monthly.
  • Water control adjustment and flushing procedure.
    • If the discharge pressure is maintaining more than required, if the discharge pressure is maintaining less than the required valve and if the sediments deposited in the valve, the flushing is required.
    • Check the sufficient water inlet pressure available.
    • To increase or decrease the discharge pressure, raise the valve opening point, turn the adjusting screw, located at the top of range spring housing, counterclockwise. To close the action in reverse.
    • Clear the sediment that might accumulate valves may be manually flushed. Insert screwdrivers under both sides of the valve spring guide and lift upwards to flush the valve.
    • Manual flushing does not affect valve adjustment.
    • The valve adjustment frequency to remove the sediments shall be after every month
  • Maintenance of Refrigerant pump
    • This is required when some maintenance activity to be done on the refrigeration system such as expansion valve replacement, oil separator replacement.
    • Check the cooling water under circulation at given temperature and pressure.
    • Close the valve 411.
    • Activate the maintenance button.
    • Switch in the required compressor.
    • Check the suction pressure below 15 PSI.
    • Close the valve 406
    • Stop the compressor.
    • Deactivate the maintenance mode.
    • Now the entire available refrigerant pumped in to water condenser.
    • Checking frequency shall be quarterly.
  • Refrigerant Charge Procedure
    • The maintenance activity is needed when the liquid indicator shows bubbles in it.
    • Refrigerant got released through relief valve any breakage in the copper tubing and led to refrigerant leakage.
    • Use the proper manifold with dual gauge.
    • Use the appropriate refrigerant.
    •  Attach the manifold.
    • Bleed the refrigerant at compressor suction valve side.
    • Open the cylinder valve.
    • Slowly open the suction valve and charge the refrigerant slowly.
    • Charge the refrigerant till all the bubbles goes off.
    • Check the compressor inter-stage cooling.
    • Check the discharge pressure while charging the refrigerant.
    • The frequency of charging port will be as needed.
  • Refrigerant Purge Procedure
    • Refrigerant purge is required although the water temperature and pressure are within the limits but the discharge pressure going higher than required and when excess refrigerant charged.
    • Check that the water condensers and clean and sufficient water flow available.
    • Attach the charging line manifold hose to pin valve just located after the oil separator.
    • Slowly remove the refrigerant through the manifold open the 411 and 406.
    • Switch the system and check for discharge pressure.
    • If it is still high again the refrigerants while the compressor in operation.
    • The frequency of charging port will be as needed.
  • Temperature sensor maintenance procedure
    • Remove the sensor from locations.
    • Check for ends.
    • Cut the end leads.
    • Properly remove the insulation (1/2”)
    • Solder the two wires.
    • Sensor ready for use.
    • Checking of the temperature sensor after every month.
  • Check and replacement of module fuse procedure
    • When the PLC shows output status on but physically the output is not on or fuse may fail due to short circuit on the output, then the fuse checking and replacement is necessary.
    • Remove the Fuse carrier and check if it is okay replace back.
    • If fuse blown replace the same with good one.
    • Switch on the output on this output module and check for output on status.
    • If again fuse blown check the wiring for any short circuit or coil failure on this output.
    • The checking of fuse frequency shall be after every month.
  • Cleaning of water cooled coil condenser
    • The cleaning is needed if the discharge pressure going beyond limits although the cooling water pressure and temperature are within limits or there is no water flow from the water condenser more of scaling on the copper tubes.
    • The checking of coil condenser shall be after every three months for the fouling and scaling.
    • Switch off the mains power supply.
    • Use proper de-scaling chemical and de-scaling system.
    • The procedure of cleaning of water cooled condenser as follows.
    • Close in the valve.
    • Remove the water control valves.
    • Remove the return water line.
    • Connect the de-scaling pump outlet at the location of water inlet.
    • Start the de-scaling and continuously run for 2 hrs.
    • Flush the same with fresh water.
    • Fix back all the removed lines.
    • For extensive cleaning open the end covers.
    • The copper tubes will get exposed.
    • Use proper size brush with extension rod and brush the same one end to another end.
    • Fix back the covers.
    • If required replace the gaskets.
  • Checking of pipeline and fittings
    • Physically check all the pipe line supports and clamps and tighten them if found loose.
    • Physically check the tri-clover clamps on pipeline and fittings for leakages. If any leakage is present then physically check the silicon gaskets, if found damaged (cut, deform, leached, shape changed) replace the same and tighten the clamp.
    • Checking shall be done six monthly.
  • Checking of Diaphragm Valve
    • Check the valve for smoothly movements, if the operating hand wheel of valve is found jam med or stuck, then open the valve and carry out the maintenance as follows.
    • Switch of the pump.
    • Close the nearby upside and down side valves.
    • Open the TC ends, loose the diaphragm valves nut by the Allen key, check the valve for damaged diaphragm, clean the valves, and check for the locking nut of diaphragm.
    • If gasket found damaged (cut, leached, deform, shape and size change) change the diaphragm.
    • After physically checking of diaphragm valve, refit in to the system and check for leakage and valve operation if found satisfactorily then it is okay otherwise replace the valve.
    • For actuated diaphragm valve check for the performance of actuator for valve opening and closing as per interlocks of the system
    • Checking of valve shall be done monthly.
  • Checking of pumps
    • Physically check the pump for any abnormal noise if heard, disconnect the pump motor wiring.
    • Disconnect the pump from the pipeline and open the pump.
    • Physically check the condition of bearings, mechanical seal, shaft, impeller and replace if found damaged.
    • Pumps need to be inspected every three months.
  • Checking of instruments
    • Ensure that the installed instruments are calibrated.
    • Physically check the end connection and terminal connections are tight; if required tightens the same.
    • Checking of instruments shall be done monthly.
  • Checking of printer
    • Check the printer for paper alignment and printer cartridge ribbon.
    • Checking of printer shall be done after very six month.
  • Checking of Spare Parts
    • Check the availability of spares before doing preventive maintenance
Sr. No. Spare Part Descriptions
 1 Refrigeration System
 2 Filter Dryer 1 each for 1 set of ref system
 3 Solenoid valve for freeze / control / condenser.
  4 Gaskets
 5 Product Chamber Gasket
 6 Condenser Chamber Gasket
 7 PLC and Control Related Spares
 8 Output Module
 9 Shelf in Sensor
 10 Condenser Sensor
11  Product sensor
 12 Power Contactor
 13 Manual Diaphragm Valve
 14 Manual Diaphragm Valve
 15 Manual zero dead leg valve
  • Preventive Maintenance – Electrical
  • Checking of terminals and wiring
    • Ensure that the power supply to the panel is switched off.
    • Visually check all the power and control wiring and terminals in the electric control panel and at field instruments.
    • Check and ensure by using screwdriver that all the wires are properly tightened.
    • Checking shall be done six monthly.
  • Checking of contactors
    • Switch off the main switch on the electrical panel.
    • Disconnect all the control and power wires from the contactor terminals.
    • Remove the dust from control panel with help of air blower.
    • Remove the contactor from the panel and visually check all the contacts for pitting and carbon deposits on the contacts.
    • Clean all the contacts with carbon tetra chloride or with contactor cleaner. Replace the contacts if found damaged or welded.
    • Put back the contactor in the panel and connect all the wires to the original locations.
    • Check the earthing of the panel body.
    • A good earthing shall show less than 2 Volts between the Neutral Wire of the Incoming Power supply and Panel Body.
    • Checking of contactors shall be done six monthly.
  • Checking of motor
    • Check the insulation resistance of motor winding with the help of meager.
    • Check the phase continuity and winding continuity of motor with the help of tong tester.
    • Physically check the motor terminal box and terminal connections.
    • Check the voltage drawn by motor with the help of multimeter
    • Check the current drawn by motor with the help of tong tester.
    • Physically check the direction of rotation; it should be as per recommended direction.
    • Checking shall be done after every six month.
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  • Checking of PLC
    • Check the PLC for blinking of LED.
    • Check the display.
    • Check the wiring contacts, if required tight the same.
    • Checking of PLC shall be done after every six month.
  • Checking of Isolation Valve
    • Check isolation valve for its proper functioning.
    • Tight all respective flange bolts.
    • Replace bottom dummy cap O-ring.
    • Checking of isolation valve shall be done every year.
    • Replacement of isolation valve shall be done after every 2-3 years if required.
  • Post Preventive Maintenance – Check List
    • Record the PM details as per the Format No.: SOP/EN/XXXYYY “Preventive Maintenance Checklist & Record for Lyophilizer”.
    • Whenever any modifications and major works are carried out to the equipment, the same shall be mentioned in the equipment history card as per the respective SOP.
    • Connect the equipment main power supply and start the equipment.
    • Ensure that the equipment is running smoothly, without any abnormality.
    • If any abnormality is observed in the above, same will be attended in co-ordination with User department Head.
    • CRF No.   :     Change Request Form number
    • QA            :     Quality Assurance
    • MMI          :     Man Machine Interface
    • PLC           :     Programmable Logical Controller
    • LED          :     Light Emitting Diode
    • Lyophilizer Maintenance Manual
    • SOP shall be distributed to following departments Quality Assurance, Engineering as per user request.
    • Preventive Maintenance Checklist and Record for Lyophilizer                     :SOP/EN/XXXYYY


Equipment Name   Location  
Equipment ID   Frequency  
Things to be done: Check List Remarks
Monthly Check List    
Check the oil level in the vacuum pumps; if not full top it.    
Check the refrigerant standing pressure.    
Check the compressor sight glass for oil level.    
Check for the level in the expansion tank    
Check the level in hydraulic tank.    
Checking of solenoid valve    
Water control valve adjustment and flushing to remove the sediments deposited in the valves.    
Check by visual inspection for any leakages around the unit; if found rectify the same.    
Change the vacuum pump oil at every 250 running hrs.    
Calibration of sensor test.    
Checking the terminal connection of the temperature sensor.    
Checking of module fuse.    
Checking of diaphragm valves and gaskets.    
Checking of hydraulic system    
Replace all the Chamber/condenser drain line flange gaskets.    
Check product chamber gaskets, if required then change.    
Check the condenser chamber gasket, if required then change.    
Check all sanitary gaskets, if required then change.    
Quarterly  Check List    
Checking and maintenance of refrigerant pump.    
Cleaning of water cooled coil condenser.    
Checking of pump for abnormal sound; if heard; then check for bearings; mechanical seal; shaft; impeller.    
Checking of compressor oil filter.    
All silicon gaskets shall be replaced.    
Half Yearly Check List    
Ensure that the installed instruments are calibrated.    
Check the heater amperes.    
Check for all compressor amperes.    
Check for water pumps amperes.    
Check for all vacuum pump amperes.    
Check for hydraulic pump amperes.    
Check the oil level inside the bellow.

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