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Laboratory Autoclave Parts and Functions

    In this laboratory autoclave parts and functions post we have briefly explained about autoclaves definition, autoclave instrument principle, types, components, uses, advantages, and limitations of autoclave instrument.

    Autoclave Instrument

    Autoclave instrument, often known as steam sterilisers, are commonly employed in medical and industrial settings. Autoclave instrument is a machine that kills hazardous bacteria, viruses, fungus, and spores on goods that are placed inside a pressure vessel using steam under pressure. 

    The goods are heated to a sterilising temperature and held there for a set period of time. The moisture in the steam efficiently transfers heat to the objects, destroying the bacteria and spores’ protein structure.

    Autoclave

    Laboratory Autoclave Parts and Functions

    Principle

    Autoclave instrument is a device that sterilises equipment using the moist heat sterilisation concept, in which saturated steam is created under pressure to kill microorganisms such as bacteria, viruses, and even heat-resistant endospores. This is accomplished by raising the temperature of the instruments within the device above the boiling point of water.

    Gas laws, which dictate that the higher the pressure within the device, the greater the temperature rises, are likewise embodied in this process. To put it another way, pressure and temperature are directly proportional.

    It’s also worth noting that the temperature, not the pressure, is what kills the germs. Higher pressures, on the other hand, can raise the boiling point of water, which raises the sterilisation temperature. The rapid propagation of heat within the material is further aided by high pressure.

    Steam sterilisation works because the moisture in the steam aids in the coagulation of the proteins that germs feed on. Coagulating the proteins incapacitates and finally kills the bacteria.

    Autoclave instrument normally achieve a temperature of around 121 degrees Celsius, and the sterilisation procedure takes about 15-20 minutes. Autoclave instrument cycles, on the other hand, can be regulated by the working technician.

    Autoclave

    Laboratory Autoclave Parts and Functions

    Components/Parts

    Autoclave instrument is used to sterilize equipment and maintain it free of microorganisms.  They do this by cleaning and sterilizing the equipment placed inside them with steam and high pressure. Autoclave instrument is used in laboratories and other industrial settings where equipment cleanliness is critical, such as food processing.

    1. The chamber

    This is the main compartment of the autoclave instrument, where the things to be sterilised are placed. They come in a variety of sizes, ranging from 100 to 3000 litres, and have both an inner and an outside chamber. This outer chamber is called as a ‘jacket,’ and it is filled with steam to speed up the sterilising process.

    2. The Door

    The autoclave instrument front door is designed to keep the outside atmosphere out. This ensures that the items inside the chamber are adequately sterilised. The contents are secured and leaking is prevented with a lock and a door seal.

    3. Safety Valve

    Steam is fed into the chamber at a higher ambient temperature through a conduit at the bottom of the cylinder. The temperature rises by 20 degrees Celsius above the typical boiling point of water as a result of the increased pressure. As a result, a safety valve is installed to prevent the pressure inside the chamber from rising above a predetermined maximum temperature.

    4. Regulator

    A thermostat starts a timer once the target temperature is attained. Depending on the contamination level of the materials inside the autoclave, the timer is normally set at 15-20 minutes. The way in which they were loaded into the chamber will have an impact on the timing as well.

    5. Pressure Unit

    A whistle is present on the autoclave’s lid, which is identical to that of a pressure cooker. By elevating itself, the whistle adjusts the pressure inside the chamber by releasing a set amount of vapour.

    6. Cooler

    Many autoclave instrument will have a system in place to chill any wastewater before it is discharged into the sewer. This is frequently done to prevent damage to the laboratory’s drain pipes.

    Autoclave Types

    Despite the fact that autoclave instrument come in a variety of shapes and sizes, they all work in the same way. The type of autoclave instrument to employ is determined on the application.

    1. Laboratory Bench Autoclaves: This type of autoclave is widely utilised all over the world. It has an air and steam discharge tap, as well as a pressure gauge and a safety valve. At the bottom of the chamber, there is also an electric immersion heater.

    2. Gravity Displacement Autoclave: In laboratories, these are commonly used. This autoclave uses a heating unit to generate steam inside the chamber, which can travel around the chamber for efficient sterilisation. In comparison to other autoclaves, it is also quite inexpensive.

    3. Positive Displacement Autoclave: This type of autoclave uses a separate steam generator unit to generate steam, which is then transferred into the autoclave. Steam may be generated in seconds; hence it is known to be speedier.

    4. Negative Displacement Autoclave: A steam generator and a vacuum generator are both present in negative pressure displacement autoclaves. The vacuum generator draws all of the air out of the autoclave, whereas the steam generator, like the positive pressure displacement autoclave, generates heat and passes it into it. This is the most popular autoclave, but it is also the most expensive.

    Autoclave

    Procedure

    1. In general, an autoclave instrument is heated to 121° C for at least 30 minutes using saturated steam at a pressure of at least 15 psi. The steps to take when using an autoclave are as follows:

    2. Look inside the chamber to see whether there are any previous instruments.

    3. Fill the chamber with water and double-check the amount.

    4. Insert the instruments into the chamber.

    5. Tighten the screws on the lid, and then turn on the electric heater.

    6. Adjust the safety valves to keep the chamber at the proper pressure level.

    7. When no more bubbles emerge from pipe, displacement is complete.

    8. Shut the water supply and wait for the steam to reach the desired temperature.

    9. Blow the whistle to release all of the surplus pressure.

    10. After the whistle, let the autoclave operate for the specified amount of time.

    11. Turn off the electric heater and let autoclave to cool.

    12. Allow air from outside the autoclave to enter by opening the discharge line.

    13. Remove the instruments from the chamber by opening the lid.

    Uses

    1. Because materials containing water cannot be sterilised by dry heat sterilisation, autoclaves are essential instruments for ensuring their sterilisation. Autoclave instrument are also utilised for a variety of other reasons.

    2. Autoclave instrument utilised to sterilise media, tools, and lab ware as well as decontaminate specific biological waste.

    3. Before being disposed of, medical waste that may contain bacteria, viruses, or other biological materials should be autoclaved to kill any bacteria, viruses, or other biological materials.

    4. Autoclave instrument are used in medical labs to sterilise medical equipment, glassware, surgical instruments, and medical waste.

    5. Sterilization of culture material, autoclavable containers, plastic tubes, and pipette tips is also done in autoclaves.

    Safety

    1. When unloading the autoclave instrument, wear appropriate Personal Protective Equipment (PPE) such as a lab coat, heat resistant gloves, and eye protection.

    2. If there is water coming out the bottom of the autoclave, never open the door. A build-up of scalding water can be caused by clogged steam lines, equipment failure, or clogged drains.

    3. To avoid steam burns and shattered glassware, wait until the pressure drops to zero and the temperature drops to or below 121°C before opening the door at the end of a cycle. Standing right in front of the door is not a good idea.

    4. Never overheat liquids. When liquids reach temperatures above their normal boiling point but do not appear to be boiling, this is referred to as superheating. Any movement of the liquid could cause it to violently flash to steam and spray.

    5. Superheated liquids may boil out of their containers or explode in situations where personnel are rushing to remove flasks or bottles from the autoclave.

    Further Readings

    Reference

    1. https://prosystem.euronda.com/what-is-the-best-autoclave-for-a-dental-practice/
    2. https://www.enbio.com/uk/blog/post/autoclaves-types-and-classes
    3. https://www.cdc.gov/infectioncontrol/guidelines/disinfection/sterilization/steam.html
    4. https://plantcelltechnology.com/blog/autoclave-principle-types-and-precautions/