Highlights from Medica 2015

MEDICA is the world‘s largest medical marketplace held annually in Düsseldorf Germany. It's a great opportunity to meet existing and new customers and showcase our technology, which is one of the most advanced sterilization technologies currently available. Whoever's interested in sterilization, visited our booth and was greeted by one of our team members. Our stunning booth redesign was the ideal setting to introduce key innovations in a range of products.

Although red is our favorite color, Tuttnauer has recently gone green with the EcoWater-Chiller for Horizontal Autoclaves. This is a Chiller system that minimizes water consumption by as much as 90% compared with building chiller. Yes, Tuttnauer has taken a big step towards preserving the environment. 

EcoWater Chiller for Horizontal Autoclaves

The high end solutions we offer are not always suitable for institutions working on a limited budget.  Under certain conditions an economic autoclave with quality features is the best choice. The new 5075HSG autoclave with two Automatic doors is designed to answer this need. It is an ideal sterilizer for medical centers and large clinics that need a pass-through wall installation. It's a cost-effective solution compared to Tuttnauer's high end small capacity horizontal autoclave.

The tabletop category was not neglected. We introduced the Elara 11i – Economic Class B Autoclave, a 28.5 liter pre & post vacuum autoclave with steam generated inside the chamber and economically priced. The autoclave includes 6 light weight trays, made of 316L stainless steel.

Elara 11i Tabletop Autoclave - Tuttnauer

The New D-Line Tabletop Autoclaves - 2340 & 2840 EK/EKA with Powerful Heaters. These autoclave models now include more powerful heating elements which speed up cycles.

Socializing at Tuttnauer

The booth was bustling with crowd and since a large number of key players from Tuttnauer attended Medica 2015, everyone who entered our booth was greeted with a drink, a smile and valuable information about our products and about autoclaves and sterilization technology.

The highlight was at the party we hosted. Live music, dance, drinks – everything needed to relax and bond with new and old friends.

For those  who visited our booth at Medica we'd like to thank you for connecting with us. Please keep in touch. And don't hesitate to tag us or post pictures from the event, so we can get your take on Medica 2015. We would also like to thank Medica for the opportunity to connect with the people that make medical industry what it is.

Here are some pics from the event.


The Autoclave Steam Generator

Now that we understand steam, its properties and quality we can move ahead and learn about how steam is generated and enters the autoclave. Ready? We're moving full steam ahead.

The Function of the Autoclave Jacket

Did you know that most large autoclaves, like horizontal autoclaves, wear a jacket? Why?  One of our upcoming posts in the series focuses on the autoclave jacket, which will reveal why we dress up the autoclave. For now it is important to understand the function of the jacket because it helps us understand how steam from the steam generator reaches the chamber. Steam supplied from the generator heats the autoclave jacket and circulates inside the jacket readily available for instant use. In a CSSD (Central Sterile Supply Department) or SPD (Sterile Processing Department) autoclave that sterilizes medical instruments, the autoclave jacket surrounds the chamber thereby heating the chamber, and in some configurations the jacket functions as the autoclave chamber steam source.  A valve located between the jacket and the chamber opens letting steam from the jacket enter the chamber, which is then used for sterilization.

There are, however, exceptions. Steam supply from the jacket is applicable to hospital autoclaves, such as those found in the CSSD (also called the SPD). In the case of some autoclaves different steam types are used for different purposes. "Dirty" steam is used to heat up the jacket and is used from either the steam generator or the building's steam. Dirty refers to the quality of steam that is produced. Obviously it is not dirty, it just means that the quality of steam produced is not the highest quality, which is fine in many cases such as instrument sterilization in hospitals or the medical industry.  Clean or "pure" steam that comes in contact with materials that require sterilization is generated without coming into contact with any heating elements that can reduce the quality of steam.

What is Clean Steam?

Conventional steam, also known as dirty steam, contains foreign particles from chemicals, from the metal and from the feed water. Normally this does not cause any problems and can be used in many applications such as in hospitals when sterilizing medical instruments. But even though the steam temperatures and humidity are according to requirements for killing most germs, conventional or “dirty steam” cannot be considered 100% clean.

Clean steam is commonly used in high containment BSL3 (biosafety level 3) laboratories that require a higher quality of steam. High quality steam is needed for tissue culture work, sterile water preparation and other special processes. Building steam is not suffiecient to produce clean steam. Clean steam will be produced by a steam generator that uses pipes and fittings that are constructed from stainless steel and brass and pneumatically operated valves, which reduce maintenance and downtime. Stainless steel piping, fittings, and components are made of a higher grade of stainless steel called 316L.

The highest grade of pure/clean steam is generated by a steam to steam generator. The steam is produced by using either the buiding steam or steam from a steam generator. The steam produced  does not come into contact with heating elements. Typical uses for this type of clean steam include pharmaceutical applications and food processing

Which Steam Generator Suites Your Autoclave?

Let’s zoom in and examine the different steam supply solutions available. We will understand why and when each solution is used. Ideally, it is preferred to supply steam to the autoclave from a dedicated built-in or stand-alone steam generator, which is designed and constructed for the sole purpose of steam supply for autoclave sterilization. A dedicated steam generator , whether built-in or stand alone is designed with an optimal operating pressure, quality piping and components to ensure that the process of sterilization by steam is not compromised.

Is your Autoclave Steam Generator Introverted or Extroverted?

Autoclaves don't have personalities, but the autoclave steam generator can be positioned either under the autoclave, this is called a built-in steam generator, or it can be external to the autoclave, an independent standalone steam generator.

The main consideration when deciding between a built-in or a standalone steam generator is the size of the autoclave, whether it’s a single or double door autoclave and the steam generator's size. Every CSSD prefers a built-in steam generator with the obvious space saving advantages. Sometimes the autoclave is just too large and then there's no other option but to position it by the side of the autoclave and there were even cases when the steam generator was on top of the autoclave.

Tuttnauer Tabletop SterilizerTuttnauer autoclave with built-in steam generator

Dual Steam Supply for Your Autoclave - Why Not Enjoy Both Worlds?

If you want to enjoy both worlds Tuttnauer supplies a hybrid steam supply solution - the dual steam supply autoclave. An autoclave with a dual steam supply has two steam lines connected to the autoclave: One line supplies steam from the building’s steam network and the second line supplies steam from a dedicated steam generator. The main reason for selecting an autoclave with a dual steam supply is in cases when building steam supply is irregular and affected by unstable environmental conditions. Another reason to choose an autoclave with a dual steam supply is that there are times when the availability of steam is turned off. Hospitals sometimes turn off the steam supply in the evenings and nights and often the autoclave needs to function 24/7 to keep up with high instrument turnaround. This is when the dedicated steam generator will kick inn. If  the autoclave needs to be ready and functioning at all hours, then having a dual steam supply is important.

Tuttnauer Tabletop SterilizerA hospital's boiler room
Tuttnauer Tabletop SterilizerStandalone Steam Generator

Steam to Steam

An alternative way to generate steam is the steam to steam generator, which is also called a clean steam generator. As discussed, this steam is used usually only in advanced laboratories or pharmaceutical autoclaves. It is needed in cases that the level of sterilization requires the steam to be pure when the quality of building steam or standard steam generator is not high enough. It uses plant steam which is called “dirty” steam to generate pure steam. The steam that enters the chamber was produced from water that did not come into contact with heating elements. The water turned into steam by steam and therefore the water doesn't come into contact with electrical parts.

Clean steam uses the energy of the "black" steam for generating steam, instead of using electricity to generate steam. This saves a connection to a high current steam generator by using the building steam to generate the clean steam.


We hope you are now familiar with how steam works, its quality and the different options of autoclave steam generators and steam supply. After we've raised the pressure of the autoclave with steam, we will dramatically reduce it and see how vacuum works in an autoclave and why it is needed. We will explain the ins and outs of the vacuum. What is deep vacuum? Why do we pulse? Why is getting rid of the air important for sterilization assurance? and more. Stay tuned.

But before we take the pressure down, we want to hear from you. How is steam supplied to your autoclave? Did you ever encounter any difficulties or challenges with steam supply?  Let us know and if you have questions, we can provide some good answers.


Autoclave Sterilization Process Guide

What is an 'autoclave,' and how does it work? We'll focus on the autoclave sterilization cycle process and walk you through the different autoclave cycle stages.  After reading all the material in this series you’ll know how an autoclave works. Knowledge is power, and an autoclave user, technician, or operator is more effective and efficient if he or she understands the different stages of the sterilization process. This series will cover all aspects of autoclaving, including:

SEE the new blog series about Autoclave Sterilization Basics which discusses topics about autoclave sterilizers and sterilization.
  • Steam generators and steam supply 
  • The pre and post vacuum phase of the sterilization cycle
  • The autoclave jacket 
  • The cooling process
  • The autoclave control systems

What is an Autoclave?

The invention of the autoclave sterilizer is attributed to Charles Chamberland, in 1879. Around that time, researchers started to understand the advantages of sterile surgery, and doctors needed a more reliable sterilization method than open flaming. The autoclave’s benefits were soon evident, and it became an essential part of every clinic and hospital. 

An autoclave is used to sterilize surgical equipment, laboratory instruments, pharmaceutical items, and other materials. It can sterilize solids, liquids, hollows, and instruments of various shapes and sizes. Autoclaves vary in size, shape and functionality. A very basic autoclave is similar to a pressure cooker; both use the power of steam to kill bacteria, spores and germs resistant to boiling water and powerful detergents.

Tuttnauer's Automatic Tabletop SterilizerA very basic autoclave resembles a pressure cooker
Tutnauer Sofisticated Horizontal AutoclaveThe most advanced autoclave cannot be compared to a pressure cooker though their basic functions are similar.

What is an Autoclave Used for?

An autoclave chamber sterilizes medical or laboratory instruments by heating them above boiling point. Most clinics have tabletop autoclaves, similar in size to microwave ovens. Hospitals use large autoclaves, also called horizontal autoclaves. They’re usually located in the the Central Sterile Services Department CSSD) and can process numerous surgical instruments in a single sterilization cycle, meeting the ongoing demand for sterile equipment in operating rooms and emergency wards.

Tuttnauer Tabletop SterilizerSmall autoclaves, also known as tabletop autoclaves, can be found in dental offices.
CSSD's Horizontal AutoclaveA large autoclave in a CSSD

Generating Steam and Steam Quality

Steam is the autoclave’s sterilization agent. In our Sterilization Methods series, we explained the physics of steam and why it’s ideal for destroying microorganisms such as bacteria and spores. Part 1 of this post will explain how steam is generated for autoclaving purposes. Part 2 in this series will discuss the various types of autoclave steam supply and generation and when each is used.

Back to the Source

The ANSI/AAMI sterilization standard states: 

There are two common sources of steam used for sterile processing: hospital steam boiler systems and self-contained electric boilers. In both cases, treated water supply is necessary to remove total dissolved solids (TDS). Each system should be designed, monitored, and maintained to ensure that the quality, purity, and quantity of the steam provided are appropriate for effective sterile processing (see: https://www.health.qld.gov.au/chrisp/sterilising/large_document.pdf)

Tuttnauer provides autoclaves that connect to the building or hospital steam supply as well as models equipped with self-contained electric steam generators. Other Tuttnauer autoclaves are fitted with a double-steam option (capable of changing steam supply source according to building steam availability) fitted to user requirements. The autoclave steam generator is either built-in or stand-alone, depending on chamber size.

Autoclave Steam Quality

When it comes to transferring large quantities of energy to an object requiring sterilization, nothing’s more powerful than steam. After all, steam engines propel ships and trains. Even the Titanic was powered by steam.

We discussed steam quality in a detailed post on sterilization methods, but let’s review the factors that determine this quality, because it’s crucial for proper autoclave functioning and the sterilization process as a whole. Two parameters are most important: 

  • the level of non-condensable gases
  • the moisture level

The optimal composition of steam within an autoclave is 3% liquid and 97% gas. Any change in the percentage of moisture increases or decreases sterilization time. In practice, sterilization time is calculated according to optimum steam conditions and steam’s ability to transfer energy to the non-sterile load prior to sterilization. After all, one of the most important benefits of steam autoclave sterilization is that it requires considerably less time and heat than a dry heat sterilizer, due to steam’s capacity to transfer energy.


Dry Steam? Wet Steam? Not in the Autoclave

Less than 3% humidity produces what’s called dry or superheated steam. This steam increases sterilization time because it reduces energy transferability. Superheated steam lowers humidity to roughly 0%, transforming the autoclave to a dry-heat oven. The energy transfer is reduced, and what takes three minutes in an autoclave at 134°C takes two hours at 160°C and thirty minutes at 180°C!! 

However, greater than 3% humidity generates saturated or wet steam, which requires higher sterilization pressure and temperature. Wet steam also extends the drying time at the end of the sterilization process. A dry load is required at the end of the process when the load is wrapped and not intended for immediate use.

Autoclave sterilization standards and directives permit some flexibility in steam humidity levels, since it’s almost impossible to supply perfect steam at a steady flow. Even if conditions are nearly optimal, many variables affect steam as it’s transferred to an autoclave. Chief among them: weather conditions and temperature; piping quality, length, and structure; drainage stations; and availability of high-quality steam traps. 

Pick Up Steam

Now that we understand how steam works, we can examine how it’s generated and fed into the autoclave. Our next post will “pick up steam,” discussing the autoclave steam generator and explaining its different types and purposes. Stay tuned.

More about Tuttnauer autoclave sterilizers: