Studor Celebrates 40 – What else happened 40 years ago?

Celebrating 40 Years of Studor – Since 1975

2015 is a wonderful milestone in our Studor history, being when Sture met Doris and STUDOR (STUre & DORis) was conceived, so we thought we would take the opportunity to cast our minds back to 1975 to see what else was happening in this year.

Here is 1975 in words and pictures…rubix_cube

  • The Rubik’s Cube was released in the shops – a 3D combination puzzle invented in 1974 by Hungarian sculptor and professor of architecture Ernő Rubik.
  • Microsoft was created – one of the true success stories of modern times, when Bill Gates and Paul Allen joined forces to create one of the greatest businesses of them all.
  • The Altair 8800, the first of the new hobby computers started to appear.220px-The_shining_heres_johnny
  • The movies “One Flew Over the Cuckoo’s Nest” and “Jaws” were released.
  • Apollo and Soyuz spacecraft took off for US-Soviet link-up in space (15 July).
  • Margaret Thatcher was the first woman elected to lead Britain’s Conservative Party.
  • Home videotape systems (VCRs) were introduced by Sony (Betamax) / Matsushita (VHS).
  • 8,000 ceramic warriors were discovered in China.launch of apollo-soyuz test project (MIX FILE)
  • The price of petrol increased by nearly 70% in one year.
  • Catalytic converters were introduced on cars.
  • The city of Saigon was surrendered and remaining Americans were evacuated, ending the Vietnam War (30 April).
  • In the UK inflation continued to spiral out of control, reaching 24.2%.
  • And in other pipe news..the Alaska pipeline construction began!


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Nasty & Noisy No More

The Studor Trap-Vent Provides the Solution to a Nasty Smelling & Noisy Drainage System

Recently Mike Start from Dorset in the UK was experiencing nasty odours from the fixtures in his en-suite bathroom; the fixtures consisted of a wash basin, bath, shower and WC:

I had the drains cleaned, but the odour still persisted. It was suggested that the pipe system needed to be vented. I searched the internet for a solution and discovered the website. Not knowing which vent to buy and fit, I contacted the company and spoke to Tony Hill.

From my description of the gurgling noise, the odours coming from empty siphons and the multiple fixtures linked together, Tony assessed that the problem would be solved by installing a Studor Trap-Vent, which he advised is a siphon with an integrated Air Admittance Valve.

The Trap-Vent CompactHe explained that the Trap-Vent protects the water trap seals, reduces noise and provides sufficient airflow for group venting. After installation the odours have now completely disappeared and I wish to thank Tony for his prompt response and the professional service provided.

Having identified the Studor range of AAVs on their website, I have no reservation in recommending their excellent range, in particular the Studor Trap-Vent – in my book, the  solution to eliminate nasty smelling and noisy drainage systems.”

For further information on the Trap-Vent please visit our product page or contact us.

Trap-Vent Compact

The Trap-Vent Compact
Ideal for concealed locations

Trap-Vent Design

The Trap-Vent Design
Ideal for exposed locations



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World Plumbing Day 2015

march 11, every year… everywhere

Plumbing – Vital to Global Health
Because Every Day is World Plumbing Day

World Plumbing Day (WPD), which has the theme “Plumbing – Vital to Global Health”, was established in 2010 “to provide anyone or any organisation involved in the global plumbing industry with an opportunity to promote the important role played by the industry.” This annual day of recognition is held on March 11, every year… everywhere!

The WPD logo, which was designed by Anuja Khokhani of Ahmedabad, India, illustrates four key elements with which plumbing is associated – water, health, energy and environment.

In his 2015 WPD speech, Sudhakaran Nair (Chairman of the World Plumbing Council) comments that “the role of plumbers and the contribution that safe plumbing systems make to our community health are vital but seldom acknowledged”. The annual event hopes to draw awareness to the importance of plumbing throughout the world – in developed countries as well as developing countries.

He continues by highlighting that “there are challenges ahead for the plumbing community who must continue to remain abreast of new public health risks. Therefore, we the plumbing community, have a very crucial role in maintaining the health and wellbeing of citizens across the world…In conclusion, let me remind my colleagues in the plumbing fraternity that we are the first line of defence of any society against the spread of disease… Let us on World Plumbing Day reaffirm our oath to use our collective expertise to safeguard the health of our communities.”

This is an oath which Studor takes very seriously, and why we continue to be dedicated to highlighting the importance of water trap seals for human health, a key focus of WPD.

Protecting Water Trap Seals for a Healthier World

The drainage system is a key aspect of the building services, whether it is a small domestic property or a large high rise tower block. Not only does a poor drainage system provide discomfort to building occupants, thanks to bad odours and nasty smells, but it can also present a health hazard. Pathogens can be released into the air, with potential health risks including SARS (severe acute respiratory syndrome).

The only barrier between the drainage system and the living / working space with those occupying the building are the water trap seals. Therefore, the integrity of the seals must be maintained at all times – the seals must perform!

In poorly designed or configured drainage systems, events elsewhere in the drain pipework can cause negative or positive pressures meaning the trap seal is broken and, hence, compromised. Providing relevant ventilation via Air Admittance Valves (AAVs) and more sophisticated drainage ventilation products, such as the Studor System incorporating the P.A.P.A. (Positive Air Pressure Attenuator), ensures that the seals are maintained and the building is safe for its occupants.

Studor is the only organisation in the world dedicated to drainage ventilation systems. Our complete focus is on the science and technology of drainage ventilation, and not only is there a complete product range devoted to the subject, but our staff have this as a key area of expertise and experience.

Our Studor products are available worldwide, and many prestigious as well as standard projects have been completed, including a significant number in developing countries, where the health benefits are equally essential. The Studor team is always available to provide advice and assistance on the configuration and installation of drainage systems and their adequate ventilation.

World Plumbing Day provides the opportunity for a focus on water and waste health. The often forgotten matter of water trap seals and their essential role should not be overlooked!

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Branch Connections & AAVs

Why Group Venting Capacity Matters

The benefits of Air Admittance Valves (AAVs) for group / branch venting is worth explaining further.


Typically a drainage system in a building is made up of vertical pipes (stacks) and horizontal pipes (branches).

These pipes are called ‘wet pipes’ as they collect all the waste towards the external main sewer system. In order to maintain the integrity of the water trap seals, VENTILATION is required to balance dangerous pressure fluctuations, and the solutions adopted are either a network of ‘dry pipes’ or the use of AAVs (which are proven to be much more effective).

Drainage System Design

Building drainage systems, comprise of appliances such as WCs, sinks, baths, etc., which have water trap seals. The water trap seal provides the essential barrier between the sewer system and the inhabited area. Branch pipes are typically 32mm, 40mm, or 50mm for most appliances, rising to 75/100mm for WCs, run horizontally with a gradient. The branch pipes then discharge into vertical stack pipes, typically 100-150mm in diameter.

Group Venting, Drainage System Design

The buildings drainage system is designed to remove waste water, be self-cleaning, watertight and to prevent foul odours.

To ensure that the water trap seals are protected, the traps require ventilation. To prevent self-siphonage and induced siphonage, this is traditionally achieved by using a network of vent pipes for group venting of the branches, or individual vents for each appliance.

It is proven that using Studor AAVs offers a more effective method to provide ventilation, as the AAVs can be placed at the “point of need” (i.e. where air is required), and so react quickly and efficiently to maintain the ventilation requirements of the building’a drainage network.

The installation of an AAV on a branch became very popular well before the introduction of the European Design Standard EN12056-2  – particularly in the situation when the original drainage system has been amended, due to re-development or re-arrangement of the appliances, making it inefficient.

How to Select the Most Appropriate AAV

Mini Vent

Firstly, over ventilating a branch is NEVER an issue, but under-venting IS, which links to the second point: Which part of the branch needs protection / ventilation?

As the first point is very much self-explanatory and intuitive, the second point is probably the most important one to consider, as it underlines the fundamental aspect that all traps connected to the same branch interact with each other.

Basically a pressure fluctuation in a branch, if not properly balanced, will always be active and so will deplete a water trap seal; this illustrates clearly that the whole branch needs protection. The ventilation capacity is fundamental, as it should not just account for a single appliance’s trap, but for all traps connected to that same branch.

Unfortunately, too often the solution adopted is based on installing a simple “anti-vacuum trap” as a quick fix.  However, for sure, this may not provide protection for the branch.

The ideal solution is the installation of an approved AAV that protects the whole branch – basically an AAV that has ‘group-venting’ capacity, i.e. the capacity to ventilate all traps connected.

To further elaborate on the ‘group venting’ capacity, the drainage design standard, EN12056-2, dictates that:

  • a minimum of 1.5 l/s is required (based on the calculation for System 1 with k = 0.7) to ventilate a bathroom branch with 3-4 appliances connected (excluding the WC);
  • only European standard EN12380 approved AAVs should be installed.

An approved Air Admittance Valve is an AAV that not only conforms to the EN12380 standard, but also shows clearly its ventilation capacity in litres per second (l/s).

In conclusion, an AAV with ‘group venting’ capacity is the only reliable solution to recommend to ensure full and proper protection for a branch.

The Studor Group Venting ProductsTrap-Vent Design

In addition to the well-known Mini-Vent, Studor also offers the Trap-Vent – this unique product intelligently combines AAV group venting capacity with a compact trap, making it the ideal, most practical and the only real ‘quick fix’ solution for efficient branch ventilation.


For more information or advice on the above topics or any of the Studor products, please do not hesitate to contact us.

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How-to: Ventilate a Septic Tank

Smelly Septic Tanks and Septic OdoursMaxi-Filtra sample installation

Unless you are on mains drainage, your septic tank collects all the wastewater from your house. It has no moving parts and just sits there quietly in your garden or yard. Its presence should be unnoticed, but as it needs to be vented, unless a suitable filter is used, nasty smells often surround it and spoil enjoyment of the outside space.

Eliminate smells from your septic tank with the Maxi-Filtra

The following short video features our very sturdy Maxi-Filtra filter, which is designed specifically for outdoor applications to eliminate bad odours. Its robust design means that the Maxi-Filtra can be used vertically or horizontally, and can also be installed in hard-to-reach places.

Studor® Maxi-Filtra™ from Studor on Vimeo.

The Maxi-Filtra is supplied with one carbon filter and a universal connector. It fits 90mm venting pipes without the connector and 75mm/110mm with the connector.

To fit, remove the active carbon filter from its packaging, insert into the body of the Maxi-Filtra, clip on the cap and simply push into the vent pipe. The full installation instructions can be downloaded from our product page.

The active carbon filter operates as a two-way vent, filtering air in both directions. The optional Aluminium Cover provides protection for the Maxi-Filtra when it is installed outside in the open air – it gives added insulation against extreme temperatures (-20°C to +60°C) and protection from animal/birds and the environment, i.e. inclement weather and the sun’s ultra-violet rays.

Maxi-Filtra case studyMaxi-Filtra

Click here to read a previous blog which provides an overview of how the Maxi-Filtra solved the problems of Di Hubbard with her properties in both the UK and Spain.

More information about the Maxi-Filtra can be found here.


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Safety and Design

Do you manage the risks of scalding and burning in your building or business? If so, have HSEyou considered the risk of scalding from hot water passing through the water trap beneath the sink?

The UK Health and Safety Executive (HSE) states that there is a risk of scalding and burning if a surface is above 43°C. Serious injuries and fatalities have occurred by contact with hot surfaces such as hot pipes, water traps and radiators; this is where inadequate insulation or design consideration is often not in place.

This HSE guidance is particularly relevant within health and social care environments, as there are greater burn and scalding risks associated with vulnerable people. These risks are linked to children, older people, people with reduced mobility and people with a reduced mental capacity.

Heat Test Scalding - Ketal

The Studor Trap-Vent provided a surface temperature reading of 20°C

Under test, when boiling water was poured into the sink, anonymous metal bottle traps provided a surface temperature reading of 91°C, whilst the UK’s leading plastic trap equivalent registered 73°C – both types therefore providing a high risk of scalding and burning.

By contrast, under the same test conditions, the Studor Trap-Vent provided a surface temperature reading of 20°C – significantly below the temperature which provides a risk of scalding and burning.

These tests are illustrated in this video which explores the ‘fitness for purpose’ of these three product types with the use of a thermal imaging camera – the settling surface temperature of each was recorded 3 minutes after boiling water had been poured into the sink and had passed through the trap into the drainage system.

Potentially dangerous temperatures can be clearly seen by observing the white coloured thermal radiation given off through the camera.

If we consider a vulnerable person, there is a significant risk that they may be scalded or burnt through contact with a metal or standard white plastic trap.

The HSE states:

Scalding and burning water traps, trap ven

There is a risk of scalding and burning if a surface is above 43°C.

‘Many radiators and associated pipework are likely to operate at temperatures that may present a burn risk. Where assessment identifies that vulnerable people may come into prolonged contact, such equipment should be designed or covered so that the maximum accessible surface temperature does not exceed 43°C.’

They’re only going to be washing their hands – how are they likely to have prolonged contact?

Here are a couple of possible scenarios to illustrate how prolonged contact could be a real probability:

  • Someone in a wheelchair wheels up to a wash basin and their knees or legs are in direct contact with the trap.
  • An elderly person has started running the hot tap and then has a fall which results in them being slumped against the trap.

In either of these scenarios, the risk of scalding or burning would be eliminated by installing the Studor Trap-Vent instead of a standard metal or plastic trap. Whilst both the Trap-Vent Compact and Trap-Vent Design gave low readings in the tests mentioned above, the Trap-Vent Design provides even more protection by way of cladding with integrated insulation which surrounds the inner working core.

Eliminating Risk

Installing the Studor Trap-Vent means that should a vulnerable person get close to this fitting, then there is no chance of scalding or burning as the potentially hot trap is completely insulated – something which is quite unique in the industry.

For other benefits and further information about the compact, highly styled Studor Trap-Vent please follow this link.

Here is also an information sheet provided by the HSE: ‘Managing the risks from hot water and surfaces.’


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Drainage Ventilation Case Studies

Product Applications and Benefits

Drainage Ventilation Technology. Air Admittance Valves. Drainage Systems

Studor Product Range

In recent months we have significantly expanded the number of case studies available on the Studor website and these are great examples of where the Studor product range can be found in some of the most iconic buildings in the world.

Whilst there are even more reference projects throughout our site, the case studies explore in greater depth the reasons for installing the Studor products; the benefits to the developer, user and inhabitants, as well, in many instances, the cost savings achieved.

The following sample case studies demonstrate the various product applications and associated benefits:

Air admittance valves

Nation Towers – Abu Dhabi

The O2 (Millennium Dome)
Greenwich, London, UK
The Studor Single Pipe System (SSPS), incorporating AAVs and P.A.P.A. (Positive Air Pressure Attenuator), has provided the drainage solution for the innovative and iconic 02 Arena in London, UK.

Ferrari World
Yas Island, Abu Dhabi, United Arab Emirates
The unique design of the Ferrari World Theme Park roof, sporting a massive Ferrari logo, was only made possible using the Studor Single Pipe System (SSPS), an environmentally-friendly and cost effective sealed drainage solution that avoids the need for unsightly roof penetrations.

Ford Field Stadium
Detroit, USA
Installation of Studor Air Admittance Valves (AAVs) avoided the problem of sewer gases entering the Ford Field Stadium (home of the Detroit Lions NFL football team) from the rooftop Air Handling Units (AHUs) which were situated above the concourses.

Pak Tin Estate - Drainage Ventilation Case Study

Pak Tin Estate – Hong Kong

Pak Tin Estate
Hong Kong, China
The Studor P.A.P.A. and Studor Maxi-Vent AAVs have been retrofitted throughout two high rise blocks, each of forty-one floors, on the Pak Tin public housing estate in Hong Kong.

Hamilton Harbour
Queensland, Australia
The Studor Single Pipe System (SSPS) was the chosen drainage solution for one of the fastest selling residential high-rise developments in the state of Queensland.

Nation Towers
Abu Dhabi, United Arab Emirates
The Studor Single Pipe System (SSPS) was specified for installation at Nation Towers, Abu Dhabi, because it allowed for flexibility and simplicity in design whilst also significantly reducing the amount of materials (pipework) used in the drainage system, for a more sustainable solution.

Please keep checking back to our reference projects web page, as we plan to continually expand the case study library to give you further product application examples.

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Multi-national Maxi-Filtra & Mini-Vent

Studor AAVs Prove the Solution in Spain and the UK

Di Hubbard has properties in both the UK and Spain. Coincidentally, both have needed a Studor Maxi-Filtra to solve problems with the septic tanks.

Di herself takes up the story:

Maxi-Filtra 2

Smelly Septic Tank in Spain
“One of our properties is in Spain. The installation has four toilets emptying into a septic tank. In our case, the septic tank was installed without the proper external vent to allow the system to breathe; all we had was a blocked pipe sticking out of the ground and, in time, when one toilet flushed it would suck the water from another in the house and/or fill the toilet bowl without flushing anything.

“We realised what the problem was and immediately unblocked the external vent to the septic tank which, of course, brings its own problems with smell, and so the solution was the Studor Maxi-Filtra.

Mini Vent

Nasty Smells in the UK
“In my UK house I had an AAV on the toilet in my extension because it was not connected to the main stack, so we discussed this with our UK plumber who agreed the solution was to purchase a Maxi-Filtra for our septic tank here too, which we did in 2012.

“Once fitted, the toilets and system started to work perfectly – the filter also removes the nasty smells being emitted from the tank.

“We started to experience the same problem in the last couple of months. The solution was to replace the filter as it has a two year life, and now life is perfect again!

Problem Solving with the Maxi-Filtra and Mini-VentMaxi-Filtra Filter
“We have also purchased the Studor Mini-Vent, as the builders had also plumbed the air conditioning pipes into the sewage system, so each time you ran it the smell of rotten eggs was immediately present in the house.

“Attachment of the Mini-Vent has also resolved this problem, and is a safe solution compared to the alternative use of a piece of kitchen roll stuffed into the pipe!”

All good Studor Solutions! For further details about the Studor Maxi-Filtra or Mini-Vent AAV please click on the product name links or see our website.

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Video: The Studor P.A.P.A. for Multi-storey Buildings

Here is a short video feature which helps explain the features and benefits of the Studor P.A.P.A. in dealing with positive pressures in a buildings drainage system.

The Studor P.A.P.A. (Positive Air Pressure Attenuator) is a revolutionary ‘world-first’ product developed to resolve the problems of positive pressures (transients / back-pressure) within the drainage systems of multi-storey and high rise developments.

This is the perfect complement to the existing range of Studor Air Admittance Valves (AAVs), providing a complete venting solution for any multi-storey building over 10 storeys high.

The below video feature helps explain the Studor P.A.P.A. in more of a visual format, and further product information can be retrieved here on the Studor P.A.P.A. product page.

Studor® P.A.P.A.™ from Studor on Vimeo.

Testing and Intellectual Rights

This revolutionary product was first tested in the laboratory of Heriot-Watt University in Edinburgh and was invented by Professor John A. Swaffield and Dr David Campbell. The invention of such a system remains unique in the drainage and plumbing field and is patented along with the designs of numerous other Studor products.

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Below Flood Level

As most people are aware, the flood level of a fixture (such as a wash basin) is the level at which water will begin to overflow – this could be various reasons, including a blockage in the pipe, or quite simply due to the tap having been left turned on with the plug in.

Air Admittance Valves (AAVs) are used in place of traditional secondary ventilation, not only providing savings in materials and installation time, but also superior drainage ventilation – ensuring that trap seals are fully protected, resulting in keeping bad odours within the drainage system and eliminating gurgling. The installation position of the AAV in relation to the flood level is critical.

As illustrated in the below video link, where low quality AAVs (‘B’ rated in accordance with EN12380) are used these have to be installed ABOVE the flood level of the fixture. This is because they are not able to withhold the pressure of rising water due to a blockage and they effectively become the location of the flood level. This means that additional, and commonly unsightly, pipework needs to be installed to be able to reposition the AAV above the flood level of the fixture, and thereby prevent the risk of water from flooding into the living space through the AAV.

Fitting an AAV ‘Below Flood Level’ from Studor on Vimeo.

By contrast, the Studor AAVs (which are ‘A’ rated in accordance with EN12380) are manufactured to high standards which ensure that they may be installed BELOW the flood level of the fixture up to 1 metre below, as they will not leak and will withhold the pressure of risking water due to a blockage – they are tested to 10,000 Pa.

An ‘A’ rated AAV is a solution for any single fixture, or a group of fixtures, connected to a single branch, i.e. branch ventilation in residential/domestic and commercial applications or stack.

An ‘A’ rated AAV eliminates unsightly pipework in a bathroom, for example by allowing the stack to be terminated low down, which means that it’s not obstructing the living space and the aesthetics are improved.

The European Standard EN12380 was introduced in 2002 to establish requirements, test methods and evaluation of conformity for AAVs. Setting the industry benchmark for quality and fitness for purpose, a key aspect of the standard is Table 1, which details the rating system in relation to operating temperature range and installation position in relation to the flood level of the fixtures:

Below Flood Level

The ‘A’ rating ensures that, should a blockage occur within a building’s branch or stack Sink in Bathroompipework, the AAVs below the flood level of the fixture will function correctly. It is imperative to know that, for the lifetime of the product, the AAV will operate and there will be no compromise in performance – the last thing you want to be doing is greasing the AAV’s membrane, as advised by some manufacturers, for example, because the seal has become dysfunctional after 5 years – thereby exposing the fixtures and living space to potential flooding.

All Studor products are designed and manufactured to be maintenance free, which means they are an incredibly durable, sealed unit which will last for the lifetime of the system onto which they are installed.

A Guarantee of Quality

Marked on each Studor AAV you will see the ‘A’ rating in accordance with the EN12380 standard, which provides reassurance of quality and performance. In some markets it is rare to see an ‘A’ rating on an AAV product, as not all manufacturers are prepared to guarantee longevity and ongoing performance.

By contrast, the Studor product range has been rigorously tested to and above many industry standards (including, amongst others, Australia, Europe, UK and the USA). Our finely engineered membranes have been tested to open and close thousands of times, and across a diverse temperature range.


Our confidence in our quality is supported by our unique lifetime warranty, which means that we will guarantee tightness and functionality of our AAVs for the lifetime of the system onto which they are installed – visit here for full details.

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