EPAMS siphonic system

Last updated on Mon, 07/11/2011 - 10:08

EPAMS®, stimulate your networks

A modern technique based on a dynamic principle

Traditionally, the rainwater is collected from the roof at regular points by gravity flow. The larger the roof area is, the more numerous the points are.
In the alternative method, called « syphonic », the run-off water is drained in pipeworks operating at full bore, harnessing the principle of mechanical energy conservation between the high spots, rainwater outlets, and the low spot which is the main drain.
The EPAMS® system is a combination of anti-vortex outlets preventing air entering the pipework and cast iron SMU / ENSIGN pipe system. You can thus benefit from the technical reliability of cast iron for this specific application.   

Field of use

Siphonic rainwater drainage system EPAMS® is devoted to drain run-off water from building roofs. It is particularly adapted to drain large roofs and minimize risks of overloading:

  • Logistic building, commercial buildings,
  • Public buildings like stadiums or airports*
  • Or, for roofs in high rise buildings.

*when the type of roof is covered by the Technical Approval

Operation and economy of a syphonic drainage system

In case of intense rainfall, the rainwater flows towards the outlet equipped with an anti-vortex mechanism. When the grid is half covered by rainwater -30mm- the mechanism limits the entering of air into the pipe system and initiates negative pressure.

As the speed and the water flow still increases, the air entering the system decreases; it creates suction of the water into the roof outlets. When no air is entering the pipework, the drainage capacity of the siphonic system is at its optimum level.
An EPAMS pipework consists of one or several horizontal pipes installed with no slope, connected to a downpipe.
At the bottom of the downpipe, the pipe work is increased by generally two diameter sizes – causing decompression and reduction in the flow velocity. Before connection to the main drain the system returns to gravity flow.

Compared to a gravity flow system, syphonic drainage system allows long sections of horizontal small diameter pipes with no slope. The siphonic system has a greater compactness and save useable square meters. The global cost of a siphonic drainage system and a gravity flow are differently apportioned but a siphonic project has the ability to save below ground pipe works.

Siphonic safety over gravity flow

To harness the potential energy of the water drained in the pipework, in total safety, the siphonic system has to be accurately dimensioned. It must be designed by precise rules so that the flow velocity is always under control and the pressures within the pipe work are always balanced. Furthermore, to protect the lifespan of the EPAMS siphonic systems, SAINT-GOBAIN PAM design fixes that the dynamic pressure within the system should never exceed 5 bar.

EPAMS®: rely on the outstanding properties of the PAM cast iron systems

Cast iron properties – mechanical strength and stability, thermal expansion coefficient, resistance to negative pressure, acoustic properties, resistance to fire and outstanding service life– make the EPAMS® system the best choice to design a safe and reliable siphonic system.

Rigor and professionalism

SAINT-GOBAIN PAM salesmen, trained to the EPAMS® system are at your service to evaluate your roof drainage project. When feasibility is confirmed, a technical team designs both technical study and network sizing. People specifically in charge with your project will remain at your disposal till the acceptance of work.
Their knowledge of the system will allow them the find the best solution for your drainage project.

The installation of the EPAMS® system is generally performed by installers trained to our products. The traditional assembly at work progress allows to thoroughly cope with the reality and constraints of the job site, so that 100% of the expected performances are effectively achieved.

SAINT-GOBAIN PAM is liable for the technical studies carried out. Before the acceptance of work, it delegates a staffer or third party control office on site, to check that the installation fully meets the last study.
A certificate of technical compliance is delivered, after this pre-acceptance control.