It had been invented by the late Professor John A. Swaffield and Dr David Campbell of Heriot-Watt University in Edinburgh, to resolve the problems of positive pressures (transients / back-pressure) within the drainage systems of multi-storey and high rise developments.
Prior to the research carried out at Heriot-Watt University which led to the invention of the P.A.P.A., there hadn’t been any studies carried out to define what positive transient pressures were. The last major plumbing study carried out was by Hunter (Hunter’s curve) in 1940, but as positive transient pressures had not been identified at that time, and were therefore unknown to him, he did not include this in his study.
On the whole, this lack of understanding in the industry has led to very complicated and expensive drainage venting solutions, usually as a result of trial and error, with a standard building drainage design being adapted for installation in all different types of buildings without any scientific back-up.
With buildings being increasingly constructed higher and higher, with mixed use buildings and more complicated designs utilizing modern materials and methods, the industry is now starting to understand that it must look at ways to safely vent the drainage of these buildings.
Previous research by the Heriot-Watt University team had led to the development of the AIRNET computer program, which incorporates numerical modelling and allows for a drainage system of any size to be modelled, and venting arrangements assessed. This powerful software was central to the development of the Studor P.A.P.A., and provides the industry with the scientific back-up to support the viability of building drainage designs.
Our “Seeing is Believing” Test Tower, the topic of several other recent blogs, has enabled us to clearly show the industry what really happens in the drainage system, and why the Studor System* (incorporating the P.A.P.A. and Studor-manufactured AAVs) should be the preferred solution for the drainage systems of multi-storey buildings.
However, for many, this is not enough and this is where standards and approvals are critical. The Studor AAVs conform to numerous worldwide standards, but being a unique product, the P.A.P.A. was slightly more problematic. We have worked closely with international organisations, and continue to do so, to establish standards and approvals for devices which reduce the positive pressure within the drainage system, i.e. the P.A.P.A.
Australia: “Technical Specification for plumbing and drainage products Part 463: Positive air pressure attenuator” was published in 2005, and the P.A.P.A. has held the Watermark approval (licence number WM-20006) since then. Every 2 years the Watermark licence is renewed after IAPMO has been satisfied that there has been no change to the product in production and that the relevant QA procedures and testing/performance requirements have been complied with.
– British Board of Agrément (BBA): The BBA issued certificate number 15/5224 in June 2015. This provides verification that the P.A.P.A. has been independently assessed by the BBA as being fit-for-purpose. The application and renewal process involves laboratory tests, on-site evaluations, quality management checks and inspections of production. The key factors assessed and verified in relation to the P.A.P.A. were:
- Drainage system design
- Effect on water seals
– Local Authority Building Control (LABC): The LABC issued certificate number EWWS493 dated July 2015. This verifies that LABC has independently checked the Studor System* (incorporating the P.A.P.A. and Studor-manufactured AAVs) for compliance in accordance with English and Welsh Building Regulations, and that it is also listed under the LABC Warranty scheme. When complete, the Scottish assessment will be added to the listing.
USA: “ASSE Standard #1030, Performance Requirements for Positive Pressure Reduction Devices for Sanitary Drainage Systems” was published in 2013, and the P.A.P.A. is currently undergoing intense review and testing by NSF.
This extensive coverage of approvals and recognition should provide anyone considering specifying or installing the Studor P.A.P.A. with full reassurance that it performs as stated, that its production is carried out in accordance with the highest of quality standards and that it is monitored by independent bodies.
For more information on the P.A.P.A. and/or the Studor System, please do not hesitate to contact us.
*marketed in the Middle East and the UK as the Terrain Pleura System