details about autoclave

1. AUTOCLAV
E
Submitted by
Abhijit padhi

2. Autoclave
 The autoclave is a
piece of equipment
used for sterilization
of various lab-wares
by moist sterilization
method.
 The word sterilization
means the
destruction/eliminatio
n of all forms of life
(microbial, including
spores) present in
inanimate objrcts by
means of physical or
gaseous procedures.
 Invented by Charles
Chamberland in 1879.

3. Principle and
working
 The autoclave works on the principle of
moist heat sterilization where steam
under pressure is used to sterilize the
material present inside the chamber.
 Water usually boils at 100°C under
normal atmospheric pressure (760 mm
of Hg); however, the boiling point of
water increases if the pressure is to be
increased.
 This principle is employed in an
autoclave where the water boils at
121°C at the pressure of 15 psi or 775
mm of Hg.
 When this steam comes in contact with

4. Autoclave
parts/
components
Parts/ components used are as follows;
1. Pressure chamber
2. Lid/ door
3. Pressure gauge
4. Pressure releasing unit/ whistle
5. Safety valve
6. Steam generator
7. Waste-water cooler

5. 1. Pressure chammber
The presseure
chamber is
made up of
satinless steel
or gunmetal,
which is
present inside
the out
chamber.
2. Lid/ door
 The purpose of the lid
to seal off the outside
atmosphere and
create a sterilised
condition on ht inside
of the autoclave.
 The lid is made
airtight via screw
clamps and asbestos
washer.

6. 3. Pressure gauge
A pressure gauge is
present on the lid of the
autoclave to indicate the
pressure created in the
autoclave during
sterilization.
The pressure gauge is
essential as it assures
the safety of the
autoclave and the
working condition of the
operation.
4. Pressure releasing unit/
whistle
 A whistle is present on
the lid of the autoclave
is the same as that of
the pressure cooker.
 The whistle controls the
pressure inside the
chamber by releasing a
certain amount of vapor
by lifting itself.

7. 5. Safetty valve
A safety valve is present on
the lid of the autoclave, which
is crucial in cases where the
autoclave fails to perform its
action or the pressure inside
increases uncontrollably.
The valve has a thin layer
of rubber that bursts itself
to release the pressure
and to avoid the danger of
explosion.
6. Steam generator
•An electrical steam generator or
boiler is present underneath the
chamber that uses an electric
heating system to heat the water
and generate steam in the inner
and the outer chamber.
•The level of water present in the
inner chamber is vital as if the
water is not sufficient; there are
chances of the burning of the
heating system.
•Similarly, if the water is more
than necessary, it might interfere
with the trays and other
components present inside the
chamber.

8. 7. Waste
water
cooler
Many autoclaves are provided
with a system to cool the
effluent before it enters the
draining pipes.
This system prevents any
damage to the drainage pipe
due to the boiling water being
sent out of the autoclave.

9. Procedure
1.Place the material to be
sterilized inside the
pressure chamber and fill
the cylinder with
sufficient water
2.Close the lid and put on
the electrical heater.
3.Adjust the safety valve
to the required pressure.
4.After the water boils,
allow the steam and air
mixture to escape
through the discharge
tap till all the air has
been displaced.

10. Types of autoclave
1. Pressure cooker type/
laboratory bench autoclave:
 The more modern type has a
metal chamber with a secure
metal lid that can be fastened
and sealed with a rubber gasket.
 It has an air and steam
discharge tap, pressure gauge,
and safety valve. There is an
electric immersion heater at the
bottom of the chamber.
2. Gravity displacement type
autoclave:
 In this type of autoclave, the
steam is created inside the
chamber via the heating unit,
which then moves around the

11. 3. Positive pressure
displacement type:
 In this type of autoclave, the
steam is generated in a
separate steam generator which
is then passed into the
autoclave.
 This autoclave is faster as the
steam can be generated within
seconds.
4. Negative pressure
displacement type:
 This is another type of
autoclave that contains both the
steam generator as well as a
vacuum generator.
 Here, the vacuum generator

12. Calibration
and
Validation
of
autoclave
1. Biological indicator
The most commonly used
indicators is the spores of
Geobacillus sterothemophilus.
These spores are highly resistant
to steam and serve as a reliable
indicator of autoclave. They can
withstand high temperatures and
require a specific time and
temperature combination for
complete destruction.
2. Autoclave tapes
These tapes contain a heat-
sensitive, chemical indicator that
undergoes a color or displays
specific marking when exposed to
the proper sterilization
temoerature rypically 121°C.

13. 3. Thermo-couple validation
Thermocouple is a temperature measuring device that consist
of 2 different metal wires jpined together at one end. When
exposed to heat a voltage is generated at the junction of the
wires, which is proportional to the temperature. This voltage is
then measured by a potentiometer or temperature measuring
device providing an accurate temperature reading.
4. Bowie-Dick test
 A Bowie-Dick test is a standard operational test that
laboratories can use to determine proper air removal from
their pre-vacuum autoclave chamber and to ensure their
autoclave meets the appropriate conditions for sterilization.
 Bowie-Dick test cycle was successful if the thermochromic
paper in the test pack turns completely black; this indicates

14. Application of autoclave
Autoclaves are versatile devices that find various uses in different settings. Some
common applications of autoclaves include:
1.Medical facilities:Autoclaves play a crucial role in medical facilities for sterilizing
medical instruments, including surgical tools, syringes, and other reusable
equipment. They are also used to sterilize materials such as dressings, bandages,
and linens.
2.Dental offices: Autoclaves are essential in dental offices to sterilize dental
instruments like drills, forceps, and probes. This ensures a safe and sterile
environment for dental procedures.
3.Laboratories: Autoclaves are extensively used in research laboratories,
microbiology labs, and biotechnology labs for sterilizing laboratory glassware,
pipettes, media, Petri dishes, and other equipment. It helps prevent contamination
and maintain the integrity of experiments and cultures.
4.Pharmaceutical industry: Autoclaves are employed in the pharmaceutical industry
to sterilize equipment, vials, containers, and packaging materials. This ensures the
safety and sterility of pharmaceutical products.
5.Veterinary clinics: Autoclaves are used in veterinary clinics and animal research
facilities for sterilizing surgical instruments, lab equipment, and animal care supplies.

15. Thank you