There are sectors, which we will talk about later, in which their daily operations require maintaining very high standards of cleanliness and disinfection, for which they have in their facilities areas with a SAS System (Safety Access System), which are designed according to the specific needs of each company, being the accesses, a very important part of the design.
There are several ways to program the high speed doors, service doors or sliding doors located at the entrances to these areas. The sequencing or operation of these enclosures will depend on the processes carried out inside these rooms and the operations carried out by each company, so that people, vehicles and material can access them without putting their classification at risk. This form of actuation is known as SAS opening system, airlock, or interlocking system.
What is a SAS Opening System and what does it consist of?
The accesses have a control mechanism, called SAS opening system, interlock or airlock, which conditions the opening of the doors according to the needs of each process, and serves, as we said before, to have greater control over the access of personnel and the transfer of products between these areas or zones and the outside.
Where an airlock or interlocking system is used
They are used in the accesses of controlled areas, clean rooms or clean rooms to maintain aseptic conditions of those facilities that must satisfy a high level of exigency with which the productive processes are controlled, which are subject to the international ISO standards.
There are different types of SAS pass-through, ventilated and biological, depending on the objectives and needs of each customer. These zones are hierarchically categorized according to the level of control of the chamber and the type of materials handled in it.
Pass Through SAS. These are chambers that guarantee the transfer of objects and materials safely, preventing any type of contamination in both directions, without having an air filtration system. In this area, the doors may not be opened simultaneously,
Ventilated SAS. They are the same as the previous ones, except that they include a HEPA air sweeping system for decontamination. In the case of SAS accesses with HEPA recirculation in open circuit, the doors have a control mechanism for simultaneous opening of the doors that guarantees an adequate passage of contamination-free materials.
Biological SAS accesses are distinguished from other clean room SAS by their ability to biologically neutralize materials. In the biological SAS equipment it is possible to couple a hydrogen peroxide generator, external or integrated, which complements the filtered HEPA air sweep, so in these cases, the entrance and exit doors are interlocked and cannot be opened simultaneously, and must be totally airtight so that a pressure staggering system would not be so necessary.
Sectors where interlocked doors are used
Sectors where products are handled and/or processed, or change, clothing, disinfection, for example the pharmaceutical, chemical and food sectors.
SAS systems for more than 2 doors
The image shows a floor plan of a clean room facility or controlled environment areas. The different zones and their possible functions are described here:
Description of the Zones:
- Separation Room.
Located in the upper left part of the floor plan.
Space designed for separation of processes or materials to avoid cross contamination. - Entrance Corridor
Located on the left side, it allows access to controlled areas.
It includes an airlock for access control and dressing rooms. - Chamber -60ºC
Located in the upper center of the plane.
Designed for storage of materials at extremely low temperatures. - Inactive Discharge
Located on the lower left side.
Area intended for the discharge of materials or products that do not require special protection or control measures. - Active Discharge
Located in the lower center.
Area for the discharge of active materials or products that require strict protection and control measures. - ABN Discharge
Located to the right of the active discharge.
Specific area for the discharge of antibacterial or antimicrobial materials. - CRY Room
Located on the lower right side.
Specialized area for handling and storage of cryogenic materials.
Processes and operations in controlled areas or clean rooms
The design of these areas takes into account the specific processes and operations to be carried out, ensuring that each zone meets the necessary functionality, maintenance and control requirements. Materials will move through the entry aisle and the various unloading and storage areas, ensuring an efficient and safe workflow.
This type of SAS needs a PLC automation to govern the interaction between the interlocks of the different doors, timings, etc. It should even allow discriminating between an entry cycle to the “clean” zone and an exit cycle to the “dirty” zone.
As you have seen throughout this blog it is very important to choose the right opening system according to the needs that your company may have, therefore, if you are thinking of installing a high-speed door, service or sliding door to design a SAS access, contact us, and we will advise you about the best system for your facilities.