Air lock: Air lock is a system formed in the form of a small room which has entry in and exit doors, entry doors are kept open while exit doors are kept closed. Air flow is controlled in the room so that it prevents contamination of air of inside clean room of higher level of particle control and passage outside. Facility of crossover bench for stage gowning, hand disinfection is provided in air locks. When such air lock system is placed just before the entry of a clean room. Separate airlocks are provided for Material and Man. PAL means Personal Air lock and MAL means
Pre filters of Good Standers are recommended so that load on HEFA fitter is reduced yielding good results.
Types of Air Locks
Following Three types of Air Locks are designed
Sink Air Lock: Sink airlock as name suggest, has lower pressure in the airlock compared to outer corridor and inner classified area. So that in event of one door is opened air from outer corridor or from inner classified area enter in the air lock later and removed, just like water sink.
Cascade Airlock: Inner Classified are has higher pressure than airlock, followed by Air lock has higher pressure than outer corridor. Making a cascade of pressure.
Bubble Air Lock. The airlock has higher pressure than the both inner classified area and outer corridor, making a barrier for contaminated air to come out and to enter inside the classified area.

[…] is the systematic approach for maintaining the air pressure difference between clean rooms and air locks and passages before that lets understand that, the main function of a clean room is to prevent […]