Studor Australia  presents the innovative Studor system designed as a solution for the issues caused by transient pressures within high-rise building designs.
The Studor system employs active ventilation principles to create a balanced stack system using the working combination of Positive Air Pressure Attenuators (P.A.P.A) and Air Admittance Valves (AAV), to intercept and alleviate positive and negative transient pressures near their source of generation.
The Studor system uses the simplistic design principles of a fully vented modified stack system, but replaces traditional relief vent piping with P.A.P.As, whilst group or branch venting is eliminated by installing AAVs, allowing the system to react much faster to transient pressures due to their installation at ‘point of need’. This protects trap seals from depletion, as opposed to all induct and educt venting conducted through one point at stack termination.
P.A.P.As as attenuators do not dissipate positive pressure, but instead attenuate it. Positive transients are created when waste travelling down the stack reaches terminal velocity. Upon hitting the stack bend the waste forms a water curtain across the bend followed by a hydraulic jump with the transient travelling up the stack at speeds of up to 320m/sec. The P.A.P.A is presented as the point of least resistance, and once the transient enters the P.A.P.A, it is attenuated from 320m/sec to about 12m/sec.
This attenuation of the transient prevents trap seals from being blown out, as has been found to occur on many traditionally high rise stack vented systems around the world.
The Studor system does not try to change the stack dynamics, instead allowing the stack to function normally, create transient pressures, and then use P.A.P.As and AAVs to balance the system and protect the trap seals.
There are several advantages to utilising the Studor system including reduction of the aesthetically unappealing vent terminations, ease of design as the system is based upon the same principles as a fully vented modified stack system as well as sustainability due to reduction of pipework required. Most importantly, the cost savings that can be achieved during installation are a key advantage.
Studor recently commissioned an independent investigation into the costs associated with the supply and install of the three main types of high rise sewer stack systems currently utilised in Australia and New Zealand. These included a Reduced Velocity Aerator Stack System (RVASS) based on the Sovent system, a traditional passive vented system referred to as a Fully Vented Modified Stack System (FVMSS), and the Studor system. Proving the Studor system as the most cost-effective system was a key objective of the study.
An independent hydraulics consultant was tasked with designing three different stack systems based on a high-rise apartment building under construction in Brisbane. A complete stack system design was done using the three technologies and a bill of quantities for each of the systems was created and supplied to two separate plumbing estimators, who were asked to produce estimates for the supply and installation of the systems.
The results from those estimates showed the Studor system to be 6.11% cheaper than an FVMSS and 17.46% cheaper than the RVASS system.

The Studor system combines advantages such as reduced pipework, quicker installation, resultant cost savings and a superior active vented system with a lifetime warranty to provide total peace of mind.