Steam Flashcards
What is steam a key part of?
Electricity production.
How is energy produced using steam?
Steam is used to produce most of our electricity. High pressure steam is used to turn a turbine in the similar motion to a wind turbine, except it uses the steam as the energy instead of wind.
Why do we use steam?
It carries a massive amount of energy
It is a non-toxic component in the sterilisation process and it can be recondensed and used again in certain applications. The main ingredient is water which is readily available- there is no waste product except water. The volume of steam in comparison to the water is used to generate it. This creates a huge amount of pressure within small confined spaces. We can flood the chamber with steam from a very small amount of water. This high pressure helps with the permeability of steam.
Why must we use purified water for sterilisation purposes?
It has organics, minerals and bacterial presence removed or filtered from it beforehand.
What are the three different types of steriliser?
N
B
S.
What is the type N steriliser?
The most basic process of the sterilisers, also referred to as a gravity displacement steriliser.
What is the type B steriliser?
This has the most robust processing cycle of all the equipment. Also referred to as a vacuum capable or porous load steriliser.
What is the type S steriliser?
This machine is generally a specialised piece of equipment used for a specific purpose eg. sterilising dental handpieces.
How does the type N steriliser work?
This machine heats water in the chamber and as it turns to steam it passively forces the air from the chamber. This process isn’t entirely efficient and can leave pockets of air within the chamber. This is not favourable for a high quality sterilisation process and means that we cannot process wrapped instruments or channeled or lumened instruments either. It must achieve a temperature of beteen 134-137 degrees celsius and must maintain this for a minimum stage hold of three minutes.
How does a type B steriliser work?
The first step on this machine is to rmeove all of the air from the chamber using a vacuum pump. After that it fills the chamber with steam that it has generated for the process. Because the air has been removed first, a vacuum has been created. This allows steam to be rushed into the chamber, meaning it effectively contacts all surfaces of what is being processed. It even has the capability to penetrate the wrappings of instrumentation and sterilise them through the wrappings. We can process porous items such as cotton wool swabs. It must achieve 134-137 degrees celsius and hold this for three minutes. It then has a drying stage.
How does a type S steriliser work?
This steriliser washes and lubricates hand pieces as well as sterilising them. It has a vacuum cycle but does not process wrapped instruments. It still achieves the same temperature 134-137 degrees celsius and has a stage hold time of three minutes.IT CAN ONLY BE USED FOR THE EQUIPMENT IT IS DESIGNED TO PROCESS.
What is the current guidance document for sterilisation>
SHTM 2010 referencing BS EN 285 standard.
Why is air different from steam?
Air does not behave in the same way as steam, it cannot be heated or maintain temperature the same way steam can. It is always a lower temperature than the steam surrounding it. If it is in contact with air it is not contacting steam. This means anything that the air is in contact with might not achieve its sterilisation temperature for the minimum required time.
