Astell SQUARE autoclaves give laboratories and production facilities a square chamber for processing liquids, glassware, instruments and laboratory discard. The chamber shape can make efficient use of loading space for bottles, trays and other regularly shaped items. Each steam steriliser is built to order, with options for vacuum air removal, drying and faster liquid cooling.

Choose from a range of chamber sizes from 125 to 980 litres. Standard chamber cross-sections are 500 × 500 mm, 600 × 600 mm and 700 × 700 mm in width and height, with depths from 500 to 2,000 mm. Available combinations depend on the configuration. For taller chambers and lower loading heights, first investigate the SQUARE MAX autoclave. Autoclaves with designs or chamber sizes outside the specifications of the standard Astell ranges are available as Custom Units.

The same chamber can also form the basis of a double-door or pass-through autoclave. Double-door models have a minimum chamber capacity of 250 litres.

What do you need to process

Bottled liquids and growth media take time to heat through to their centre. Load-sensed process timing starts the sterilising hold only when a representative vessel reaches the required temperature. Controlled exhaust limits boiling and liquid loss as pressure falls, while the load cools to a safe unloading temperature. Read more in Getting liquid cycles right.

Bagged discard and items with complex geometry can trap air. The cycle, air-removal options and loading pattern must allow steam to reach the material being treated. Glassware and instruments may need shelves, loading equipment or a drying stage before they are ready to use again.

Wrapped instruments, textiles and other porous loads require effective air removal. For loads that must also leave the chamber dry, specify vacuum, a heated jacket and a suitable steam supply from an integral generator or an external source.

For practical loading guidance, read Inside the cycle: A practical guide to loading liquid and discard autoclave runs.

Options that shorten the cycle

For liquid loads, cooling is often the longest part of the cycle. Cooling options such as a cooling jacket, fans and water cooling can reduce the wait after sterilisation. Air ballast provides support pressure during rapid cooling to help limit boil-over and protect suitable containers. Astell can recommend a combination for your load, throughput and site services.

Door steam and vacuum configurations

Choose a manual or automatic vertically actuated door, with or without vacuum, and a chamber size to suit your load. The product code identifies the configuration: the first letter is A for an automatic door or M for a manual door; the second is V for vacuum or N for no vacuum; and S indicates a single-door model. The numeric part specifies the chamber capacity in litres.

The final letter identifies the steam source. Direct-steam models receive steam from an external supply, such as a stand-alone steam generator, and end in D. Models with an integral steam generator end in G.

These configurations cover the 125–980 L range within the standard dimensional rules. Chambers outside those rules are specified as Custom Units. For example, AVS250D identifies an automatic-door, vacuum, single-door model with a 250 litre chamber and an external steam supply.

Explore the processes in more detail

Getting liquid cycles right

The other half of the job

Why sterile isn’t always dry

Where autoclave cycle time actually goes

Discuss your requirements

Tell us what you need to sterilise, the load dimensions and quantities, and the number of cycles you need to run. Details of the available space, access route, water, drainage, electricity and any external steam supply will help Astell recommend the chamber and options for your facility.

Call +44 (0)20 8309 2031 or request a quotation.