As an introduction, we would like to explain a bit about the history of siphonic drainage in this country.Prior to March 2007 there were no comprehensive product and design standards for siphonic drainage. The publication of BS 8490 – the current ruling British Standard for siphonic drainage – changed this.Previously, siphonic drainage was promoted by suppliers in different formats with various slants aimed at their own offerings.BS 8490 can be used dispel the “smoke and mirrors” previously employed in the market place and clarify how siphonic roof drainage systems work. We will try to show how it can work for you through the education provided during this presentation.As an aide to control over quality design and supply, we suggest that you should seek to use manufacturers with a Technical Team to provide support to the both the Design Teams and Registered Installers.
Siphonic drainage started off as a Concept invented in Finland by OlaviEbling in late 1960’sFirst major installation in Sweden in 1972.An Unregulated Industry Grew through 1980’s which led to specifiers becoming uncertain as to how siphonic should be specified and utilised.This led to UK Government Commissioned Research by HR Wallingford during the 1990’s (the HR stands for Hydraulic Research) HR Wallingford reports SR 463 & SR 473 were studies on performance of siphonic systems on flat roofs and in gutters that you can refer to but technical advances and the advent of BS 8490 makes them a little superfluous. European Standard BS EN 12056-3 introduced in 2000 which was the first standard to include a section for Siphonic drains.BS 8490 was first published in March 2007 – this is Comprehensive Siphonic Drainage Standard covering all aspects of design rainfall rate selection, design, hydraulic parameters to be met, pipe specifications, testing and maintenance.
So what is Siphonic Roof Drainage?Siphonic Drainage is an innovative solution which utilises the power of water accelerating as it falls down the vertical downpipe to generate a naturally induced siphon which in turn creates a high-performance roof drainage solution .
Why would you use a Siphonic Roof Drainage solution?Siphonic Drainage is an Engineered Solution which provides many technical benefits which we will provide examples of during this presentation It is also one of these rare products that in addition to technical benefits can also offer cost savingsIn suitable project types these savings normally range from 25% to 45%!
So to summarise Gravity drainage, we haveInefficient vortex flow into the roof drain.This vortex pulls a core of air into the pipes to allow the water to flow with the ratio being only 1/3 water to 2/3 air in vertical pipes which leads to large diameter pipes.It really is an inefficient use of the piping system.
The main principles of siphonic drainage areFirst of all the siphonic roof drain is design to prevent vortex formation and also prevent air entering the piping system.This allows the full bore of the pipes to carry the rainwater.As water without air accelerates down the vertical downpipe, it creates negative pressure and naturally generates a high performance siphonic flowUnlike gravity systems we now use the full height of the building to provide the energy for this highly efficient Rainwater Drainage Solution
So to summarise the principles of our Terrain HydroMax siphonic drainage,First of all the siphonic roof drain stops vortex formation and prevents air ingressThis allows the pipes to run full bore with water and with negative pressure being generated through the water column accelerating down the vertical pipe, the whole height of the building provides the energy to suck the water from the roof.As the pipework carrying capacity is maximised with full bore flow and high velocities with self cleaning properties you really do have an extremely efficient roof drainage solution.
One of the most common means of terminating the siphonic system is to break the siphonic action at the first manhole outside the building.In this case the manhole should be fitted with a grated cover to provide ventilation – BS 8490 calls for open area to be no less than twice the cross sectional area of the siphonic pipe. This open area does two things. Firstly it allows the air to be purged from the system during the priming process.Secondly, if the underground drainage ever surcharges, it allows the water to escape from the open grate allowing the roof to drain
The benefit is clear to see in this photograph with the pipework being able to run flat with small diameter pipes from one end of the car park to convenient downpipe locationThis picture shows the pipes running below the beams but because the pipework runs absolutely level, the pipe can run through beams as we can hit the centre line of each beam
Before using the calculation program the designer has to Obtain the design rainfall intensity from the design teamcalculate the rainfall inflows to each drain (catchment area x rainfall rate)Identify the required pipe routes (normally determined in conjunction with the architect and with a view to save on below ground drainage)Then draw the required pipe routing into the calculation program and perform hydraulic calculationPlease note it is important that the design software has all parameters in accordance with BS 8490 and clearly identifies to the designer when all these parameters are met.In this case you can see on the right hand side the various parameters required and the GREEN PASS indicating conformity.
Our advanced program will allow the design engineer to scrutinise the system and change pipe diameters to optimise the system while still clearly displaying conformity with BS 8490.
HydroMax™ Siphonic (Syphonic) Roof Drainage
HydroMax™ Siphonic DrainageLeaders in Siphonic Drainage
Topics Covered Brief History of Siphonic Drainage General Principles of Gravity Rainwater Drainage Principles of Siphonic Drainage Benefits and applications of Siphonic Drainage Installation and Maintenance
Introduction to Siphonic Drainage• Prior to March 2007, there were no comprehensive product and design standards for siphonic drainage.• As such siphonic drainage was promoted by suppliers in different formats with various slants aimed at their own offerings• The HydroMax focus is on offering high quality, sustainable products with highly accurate and user friendly design software• Our approach is to dispel the “smoke and mirrors” educate how they work in accordance with the current British and/or American Standards• Technical Support to Design Engineers and Registered Installers3
Siphonic Drainage – Brief History• Concept invented in Finland by Olavi Ebling in late 1960’s• First major installation in Sweden in 1972.• Unregulated Industry Grew through 1980’s• UK Government Commissioned Research during the 1990’s (Refer HR Wallingford SR 463 & SR 473)• European Standard BS EN 12056-3 introduced in 2000 (1st Standard to include a section for Siphonic drains)• 2005 – ASME A112.6.9 Siphonic Drain Test issued in USA• 2006 – Singapore Standard SS 525 includes siphonic drainage• 2007 – Comprehensive Siphonic Drainage Standards published in UK and USA (BS 8490 and APSE 45) 4
What is HydroMax™ Siphonic Roof Drainage?HydroMax™ is an innovative solution whichutilises the power of a natural siphon to create a high-performance roof drainage solution.
Why use HydroMax™ Siphonic Roof Drainage?HydroMax™ is an Engineered Solution which provides many Technical Benefits HydroMax™ offers cost savings normally ranging from 25% to 45%!
What is wrong with Traditional Gravity Drainage Systems? Traditional Gravity drainage systems work but they are inefficient and have a number of factors restricting performance.7
Restrictive Factors of Gravity Drainage1. The water flow-rate is dictated by the gradient available (this gradient also restricts the distance a pipe can travel).2. Multiple rainwater pipes in locations largely dictated by the gravity hydraulics rather than design team choice.3. Gravity drains require ⅔ air to transport ⅓ water.4. Vortex formation within vertical gravity pipes results in the water being transported in an inefficient spiral motion rather than straight through the pipe.5. The driving force is only the depth of ponding or ‘head’ of water above the roof drain. 8
HydroMax 125mm (5”) Drain Equivalent Flow (95 l/s – 1500GPM) Half the Diameter Half the ponding depth of the Gravity drain125mm Drain – Depth = 95mm to Discharge 95 l/s
Vertical Gravity pipes run ‘full’ at only 1/3 water⅓ water in annular flow ⅔ air core
Horizontal (Sloping) Gravity pipesrun ‘full’ at only 2/3 water
Typical Traditional Gravity Drainage System Multiple Downpipes Drainage under Building FloorExtensive Underground Drainage Sloping Underground Drainage makes for difficult routing to attenuation/harvesting
Principles of Gravity DrainageVortex motionA large amount of Airis required to move asmall amount of water.Extremely Inefficient Annular Flow Water adheres to pipe wall Central Air Core 14
Siphonic DrainageWhy is HydroMax™ different from gravity drainage? No Air! Pipes run 100% full bore
Principles of HydroMax™ Siphonic Drainage• The Siphonic Roof Drain eliminates air entering the pipe promoting water filled pipework• The full bore of the pipe work carries the rainwater• Water, without air, accelerates down the vertical downpipe, creating negative pressure and naturally generating a high performance siphonic flow• The full height of the building provides the energy for this highly efficient Rainwater Drainage Solution 16
Siphonic Drainage - How it works The inducer on the roof drain prevents air ingress- gh and soPAtmos Rainwater falling down the vertical pipe accelerates, creating negative pressure
Siphonic Drainage - How it works - gh PAtmos More Height = Greater Negative pressure
Siphonic Drainage - How it works - gh PAtmos Greater Negative Pressure = Higher Flow Rates The full height of the building provides the energyfor this highly efficient Rainwater Drainage Solution
Siphonic Drainage - How it works HydroMax Siphonic Systems are self-drainingtherefore the pipes are empty before a rainfall event Roof or Gutter HydroMax Roof Drain Tail-pipes Horizontal collector pipe Downpipe Discharge
HydroMax System with Tailpipes primed HydroMax Roof Drain Roof Pressure Tail-pipes Horizontal Collector Pipe Drop pipe Discharge
Priming of Main Pipe Work Stage 1 - Wavy or Gravity flow Air above water Gravity flow in pipework
Priming of Main Pipe Work Stage 2 - Plug flow Plug of water filling whole pipe at high velocities which achieves self-cleansing. Air pockets driven down pipeworkTests have shown that self-cleansing can be achieved at as low as 10% to 15% of the design rainfall rate.
Priming of Main Pipe Work Stage 3 - Bubble flow Water filling whole pipeAir bubbles in suspension carried at high velocity
Priming of Main Pipe Work Stage 4 - Full-bore flowNo more air entry – Air within Pipe now Fully Purged Water filling whole pipe
Fully Primed HydroMax SystemNegative Roof or Gutter HydroMax Roof DrainPressure Tail-pipes Horizontal Carrier Pipe Downpipe The full height of the building provides the energy for this Discharge highly efficient Rainwater Drainage Solution
Principles of HydroMax™ SiphonicEliminate Air IngressPipes run Full-Bore withWaterBuilding Height providesenergy for High Self-Cleansing VelocitiesExtremely Efficient27
HydroMax™ Siphonic Roof Drainage Video Click Here28
HydroMax™ Simulation of Non-Maintained Roof Click Here29
Siphonic Roof Drainage System High Performance Roof Drains No Drainage Under Building Flexible, Downpipe PositioningSignificant Reduction in Route to HarvestingUnderground Drainage or Attenuation
System Comparison Traditional HydroMax Gravity Siphonic air core water in annular flow water air core No Air water water31
Traditional Gravity Solution 530 metres Pipework Diameters 160mm to 450mm 60m 100mHydroMax Siphonic Scheme360 metres HDPE PipeworkDiameters 56mm to 200mm 32
HydroMax System Termination Manhole or Catch Pit to have Grate Cover Note: British Standard BS 8490 states the size of free area for the Grate should be twice cross sectional area of siphonic pipe. American ASPE Technical Design Standard 45 does not dictate the size of vented area. Siphonic pipework should enter manhole chamber33 above the drain invert and be clear of any standing water to ensure free discharge
HydroMax Siphonic System Termination Vertical Siphonic Important: Pipe Below Grade Drain must be vented and sized to take the Offset volume of discharge under (if required) to Gravity flow conditions. line up with below grade pipeDo not size to match siphonic Pipe diameter. Flex-Seal flexible, expansion coupling
HydroMax Siphonic System Termination Important:If siphonic drainage is utilised to drain part way down ahigh rise building –A siphon break point must be adequately vented toatmosphere at the point of transition to gravity flow.
HydroMax Siphonic System Termination Ventilated to Siphonic flow Atmosphere Break to Gravity Recommended Vent size flow being Two-Thirds Gravity Pipe size(two-thirds air to one third water in the gravity pipe)
Suitable Projects for Siphonic Drainage Retail Chains37
Suitable Projects for Siphonic DrainageRoyal Ascot Racecourse Stadia Ricoh Stadium and Arena, Coventry Stadium of Light, Sunderland
Suitable Projects for Siphonic DrainageDundrum Retail Shopping Malls with multi-level Car Parks 313 Orchard Road, Singapore
Suitable Projects for Siphonic DrainageAccommodation/Hotels/Prisons Student Accommodation, Wembley Johnstone County Ibis Hotel, Singapore Detention Center
Suitable Projects for Siphonic Drainage Hospitals Forest Park Medical Center, Dallas Mercy Hospital, Des Moines, IA
Suitable Projects for Siphonic Drainage Apartment Blocks Podium Decks
Suitable Projects for Siphonic Drainage Green Roofs
Suitable Projects for Siphonic Drainage Siphonic Drains installed at waterproofing membrane level Green Roofs45
Suitable Projects for Siphonic Drainage Airports Gimhae South Korea
Suitable Projects for Siphonic Drainage Warehousing & Distribution Centres47 110,000m² for Tesco
Suitable Projects for Siphonic Drainage Manufacturing Plants48
Suitable Projects for Siphonic Drainage Flagship ProjectsScottish Parliament 49
Suitable Projects for Siphonic Drainage Flagship ProjectsMasdar City MIST 1B, Abu Dhabi 50
HydroMax Siphonic Products 50mm Balcony Siphonic Roof DrainThis is a special drainfor multi floor balconydrainage.The drain has a built inAnti-Backflow device.Flow RateMax. = 1.5 l/s(Litres per Second) 51
HydroMax Siphonic Products 75mm Siphonic Roof Drain Our Metric series of drains come in a range of models for compatibility with all roof typesFlow RateMin. = 1.5 l/s(Litres per Second)up toMax. = 25 l/s53
HydroMax Siphonic Products 75mm Siphonic Overflow Roof Drain Our Metric series of Overflow drains come in a range of models for compatibility with all roof typesFlow RateMin. = 1.5 l/s(Litres per Second)up toMax. = 25 l/s54
HydroMax Siphonic Products 125mm Siphonic Roof Drain Our Metric series of drains come in a range of models for compatibility with all roof typesFlow RateMin. = 10 l/s(Litres per Second)up toMax. = 100 l/s55
HydroMax Siphonic Products Range of Accessories for Our Metric Series of Drains • Leafguards • Gravel Guards • Car Park Drains • Bespoke Accessories56
Wade-HydroMax Siphonic Products 3” Siphonic Roof DrainOur North American series of drains have all been tested to ASME 112.6.9:2005 – IAPMO certified (file number 5305)Flow RateMin. = 23 GPM(Gallons per Minute )up toMax. = 415 GPM 57
Wade-HydroMax Siphonic Products 4” Siphonic Roof DrainOur North American series of drains have all been tested to ASME 112.6.9:2005 – IAPMO certified (file number 5305)Flow RateMin. = 75 GPM(Gallons per Minute )up toMax. = 750 GPM 58
Wade-HydroMax Siphonic Products 5” Siphonic Roof DrainOur North American series of drains have all been tested to ASME 112.6.9:2005 – IAPMO certified (file number 5305)Flow RateMin. = 120 GPM(Gallons per Minute )up toMax. = 1300 GPM 59
Wade-HydroMax Siphonic Products 6” Siphonic Roof DrainOur North American series of drains have all been tested to ASME 112.6.9:2005 – IAPMO certified (file number 5305)Flow RateMin. = 160 GPM(Gallons per Minute )up toMax. = 1800 GPM 60
Wade-HydroMax Siphonic Products 3”, 4”, 5” and 6” Siphonic Roof Overflow DrainOur North American series of drains have all been tested to ASME 112.6.9:2005 – IAPMO certified (file number 5305) C.I. No-Hub Minimum Maximum GPM K factor Outlet GPM Inflow Inflow 3” 0.12 23 415 4” 0.08 75 750 61 5” 0.04 120 1300 6” 0.04 160 1800
Wade-HydroMax Siphonic Products 3”, 4”, 5” and 6” Drain AccessoriesLeafguards, Debris Guards, Underdeck Clamps and Bearing Pans are available for all drains. Our 3” and 4” Drains are available as Podium Deck Drains Drain shown with Debris Guard62
HydroMax Siphonic Drain Benefits• High Performance• Versatile and Compatible with any Roof• Compact for installation in gutters/scuppers• Anti Tamper Fastening of one-piece Inducer• Proven track record of Low Maintenance 63
HydroMax™ HDPE Siphonic System Pre-Fabricated in Factory Controlled Conditions with Engineered Rail Fastening System64
HydroMax™ Siphonic System60,000m² RoofOnly 4 Rainwater Downpipes draining the Main Roof65
HydroMax™ Siphonic System HydroMax™ Collector Pipe at High Level66
HydroMax™ Siphonic System HydroMax™ Pipework Installed Absolutely Flat Level at High level68
Development of Key Standards & Codes• BS EN 12056-3:2000 (includes Siphonic Drain Test)• ASME 112.6.9:2005 (Siphonic Drain Test)• ASPE Technical Design Standard 45:2007 (Design, Installation & Product Standard)• BS 8490:2007 (Design, Installation & Product Test Standard)
Development of HydroMax™• Consultation with HR Wallingford (previously commissioned by UK Government to study siphonic drainage) ensured our offering progressed the technology above competitors systems• HydroTechnic™ hydraulic calculations report extreme conditions giving high accuracy (other systems report average hydraulic conditions)• Independently tested by Hydraulic Research Centre Wallingford (HRW) for compliance with BS EN 12056-3:2000• Independently tested to ASME 112.6.9 (IAPMO File #5305)• Full Compliance with current SS525, BS 8490:2007 & ASPE 45• 100% Success Rate
Development of HydroMax™• Full Compliance with SS525:2006• Full Compliance with BS 8490:2007• Full Compliance with ASPE Design & Engineering Standard 45• 100% Success Rate
Primary and Overflow Systems Using HydroMax Overflow System can offer the same technical and commercial benefits obtained using the HydroMax™ Primary Drains• Primary Roof Drains installed at roof level or at gutter sole level• Drains direct to underground drainage • Overflow Roof Drain Inlet raised Raised Inlet to Drain to 50mm above gutter sole. • Drains to Atmosphere often at 50mm high level or to walkways or car parks • Must not connect to Primary System (as this would normally be a vent) 72
Maintenance by DesignPrimary Drain Overflow Drain Raised Inducer Level Roof Level Regional Options: Dry Season Covers for Gulf Region 73
Siphonic Drainage Analytical Design ProgramHydroMax™ provides the following:• Web based HydroTechnic™ program for easy Technical Support• Fast Accurate Calculations in full compliance with SS525, BS 8490 & ASPE 45• Advanced Edit Functions to accommodate on-site changes• Program Generation of Pre-Fabrication Drawings (Eliminates risk of human interface errors)• Exports data in electronic format for O & M files 74
Siphonic Drainage Analytical Design Program Metric VersionFollowing calculation ofUSA Version ft/in and GPM rainfall inflows and determination of required pipe routing, the Design Engineer ‘Draws’ the piping system into the calculation program
Pipe diameters are edited to find the USA Version optimum solution76 Metric Version
Key Advantages with HydroMax™• Drains independently tested to: – BS 8490:2007 – ASME 112.6.9:2005• Designs to BS 8490 or ASPE 45• Independently tested HydroTechnic™ design software (confirmed to have “unsurpassed accuracy”)• Range of High Performance Roof Drains (Outlets)• HDPE Pipes to EN 1519 (not for North American Market) 77
Key Advantages for Building Owners• High Performance, Self-Cleansing Roof Drainage System• Fewer Rainwater Downpipes routed to convenient positions providing an increased and flexible use of floor space• Proven Record of Low Maintenance• Elimination of underground drainage, manholes, etc. within the building footprint 78
Key Advantages for the Design Team• Smaller diameter horizontal pipework installed level• An Engineered Solution allowing choice of discharge locations• Flexible Pipe routing with easy co-ordination of services• Rainwater Management - HydroMax™ can route pipework to attenuation/rainwater harvesting. 79
Key Advantages for the Main Contractor• Improved Construction Build Program• Significant Cost Savings• A dry building envelope is attained at an early stage of construction allowing fit-out works to proceed earlier• Less Trench work for below ground drainage saving excavation, soil treatment, pipe laying, back fill compaction, etc.80
Engineers Training Day – Topics Covered• Key Aspects of BS 8490:2007/ASPE 45/SS 525• Hydraulic Parameters• Piping Layout Design (do’s and donts)• Hands-on HydroTechnic training• Understanding how to Edit Systems within HydroTechnic™ to cater for design or onsite changes• Specification Writing81
Information Requirements For HydroMax to Provide Concept Designs• Design Rainfall Rate• Roof Plan Drawings (AutoCAD)• Floor Plan Drawings (AutoCAD)• Sections/Elevation Drawings (AutoCAD)• Underground drainage Connections• Attenuation or Rainwater Harvesting Requirements• Gutter Profile (to allow compatibility checks)• Specification (we can provide CSI or R10 type spec.)82
HydroMax™ Siphonic DrainageLeaders in Siphonic Drainage www.hydromax.com