Terrain P.A.P.A. & Pleura Vent System




As water descends down the single stack drainage system, it creates a negative pressure that if interrupted, or is approaching a change of direction, causes the negative pressure to change to a positive pressure which then travels back up the pipe.


The Terrain P.A.P.A.® (Positive Air Pressure Attenuator) is a positive pressure reduction device that works with the Pleura Vent System which is an air pressure regulator acting as an air admittance valve - both designed to mitigate the effects of positive and negative air fluctuations in single stack drainage systems. This allows fresh air into the branch pipework or to the top of a waste or soil stack and ultimately eliminates the need for a traditional piped secondary vent system, meaning that there's no need for vent penetrations in the slab and drastically reducing the requirement for vent penetrations through the roof.


These systems have been developed to resolve the problems of positive pressures (transients / back-pressure) within the single stack drainage systems and soil stack systems of multi-storey and high rise developments, complementing the use of Air Admittance Valves (AAVs), providing a complete venting solution.


By removing the secondary ventilation pipework in commercial and high-rise multi-storey buildings, the air admittance system introduces air regulators to balance negative air pressure fluctuations and an air attenuator to balance positive air pressures. Together, they form a highly effective alternative solution for controlling the air movement within the single stack drainage system and soil stack, protecting the water trap seals of appliances within the building.


The Terrain P.A.P.A.® and Pleura Vent System will only be supplied exclusively with a Terrain Drainage System.


Use our Airflow Calculator to work out the branch and stack airflow requirement for your project.


Airflow Calculator



®P.A.P.A® is a registered trademark owned by Akatherm BV, part of the Aliaxis Group





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P.A.P.A. Brochure 2019

pdf (15.44 MB)

Terrain P.A.P.A. BBA certificate

Terrain P.A.P.A BBA Certificate
pdf (613.88 KB)
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