STUDOR Single Stack System
Photo by Thomas Tucker on Unsplash
Soil Waste System

STUDOR
Single Stack

Active Drainage Ventilation

Leading drainage
ventilation since
1975

STUDOR has been leading the world in drainage ventilation technology since 1975. Their patented Air Admittance Valve (AAV) systems provide a complete alternative to traditional roof-penetrating vent stacks — eliminating costly pipe runs, preserving building envelope integrity and delivering maintenance-free performance across all building types.

In a conventional drainage system, pressure fluctuations inside the waste stack — caused by discharging fixtures — threaten the water seals in traps. Once a trap seal is lost, foul gases from the drainage network enter the habitable space. STUDOR's active ventilation valves respond dynamically to these pressure changes, protecting trap seals and eliminating odours at source.

Fast Flow brings STUDOR's expertise to Asia Pacific building projects, providing engineering support, system design and specification services for the full STUDOR product range.

STUDOR High Rise Single Stack Testing
STUDOR High Rise Single Stack Soil Waste Drainage Solution
Fully validated and tested at National Lift Tower, UK
How It Works

Pressure-responsive
Active ventilation

Maxi-Vent
Component 01
Maxi-Vent
Installed at the top of the drainage stack in place of the conventional roof vent, the Maxi-Vent eliminates the need for any roof penetration. It opens to admit air under negative pressure and closes airtight to prevent foul gas escape — protecting the building envelope while providing full stack ventilation.
Mini-Vent
Component 02
Mini-Vent
Placed on individual horizontal branch connections, the Mini-Vent neutralises negative pressure — or induced siphonage — that occurs when fixtures drain simultaneously. Critical for medium and high-rise buildings where branch lengths increase the risk of trap seal loss from siphonage.
P.A.P.A.
Component 03
P.A.P.A.
The Positive Air Pressure Attenuator (P.A.P.A.) addresses a challenge unique to tall buildings: positive pressure surges that travel up the stack when large volumes of water discharge from upper floors. The P.A.P.A. absorbs and dampens these pressure waves before they reach branch connections and trap seals.
Key Benefits
◈
No Roof Penetrations
Eliminates conventional vent stack penetrations through the roof, preserving waterproofing integrity, improving thermal insulation and reducing long-term maintenance risk.
◎
Odour-Free Performance
Air Admittance Valves open only to admit air, never to release foul gases. Trap seals remain intact at all times, ensuring zero tolerance for drainage odours in occupied spaces.
◉
Maintenance-Free
STUDOR valves are engineered for decades of reliable service with no moving parts requiring scheduled maintenance. The system performs consistently from day one without periodic inspection or replacement cycles.
▣
Reduced Pipework
Eliminating the separate vent stack and associated branch ventilation pipework reduces material quantities significantly — one documented project saved 40 km of pipe through single stack adoption.
◇
Space Recovery
Removing vent stacks from risers and plant rooms frees up valuable shaft space and simplifies coordination with other building services, benefiting both new builds and refurbishment projects.
△
Faster Installation
Single stack configurations reduce the number of pipe runs, connections and penetrations on site — directly translating to shorter installation programmes and lower labour costs.
○
Retrofit Ready
STUDOR valves resolve common drainage problems in existing buildings — gurgling, slow drainage and foul odours — without the disruption and cost of re-piping. A proven upgrade path for ageing drainage systems.
□
All Building Heights
A tiered product system covers every building height category — from low-rise residential through to supertall commercial towers — with engineering solutions scaled to the pressure demands of each.
Ideal Applications

The right solution
for every
building type

Application 01
Low-Rise Residential
Maxi-Vent eliminates roof penetrations in houses and low-rise apartments. Standard plumbing layouts perform reliably at this height; the AAV adds the benefit of a fully sealed roof without compromising ventilation.
Application 02
Medium-Rise (Up to 12 Levels)
Mini-Vent added to branch connections neutralises induced siphonage across multiple occupied floors. Combined with Maxi-Vent, the system provides complete ventilation protection without any external vent stack.
Application 03
High-Rise (Above 12 Levels)
The full STUDOR system — Mini-Vent, P.A.P.A. and Maxi-Vent — manages both negative and positive pressure dynamics inherent in tall drainage stacks. Essential for any high-rise residential or mixed-use tower.
Application 04
Retrofit & Refurbishment
Existing buildings experiencing gurgling, slow drainage or persistent odours benefit immediately from STUDOR valve installation. Targeted retrofit without full re-piping restores drainage performance and occupant comfort.
Specify STUDOR for
your next
soil waste system
Contact Our Engineers →