Primarily Focusing on Backflow Prevention

Primarily Focusing on Backflow Prevention
July 2005 Primarily Focusing on Backflow Prevention UK WATER REGULATIONS References to the Water Regulations Guide with practical solutions Presentation By Steve Grace B-Eng FIPHE Technical Director - Arrow Valves Ltd March 2006 copyright 2006

www.arrowvalves.co.uk copyright 2006
Objectives July 2005 Fluid Categories – risk classification - New UK standards Regulations 2 – 6 – requirements and solutions Backflow – how it occurs, back siphonage vs back pressure Backflow prevention devices - Fluid Categories 2 – 5 RPZ valves – use, installation & testing Sealed heating – regulations and devices Water Fittings Approval Standards – Kiwa, WRAS Water conservation – requirements and devices Hose Union Taps - requirements and devices Temperature – limit and control Summary copyright 2006

The legal UK Water Regulations include -
Regulations & Guidance Available Information July 2005 The legal UK Water Regulations include - The Water Supply (Water Fittings) Regulations – Statutory Instruments 1148 Schedule 1 – Fluid Categories Schedule 2 – Requirements for Water Fittings Guidance is produced by DETR (DEFRA) and WRAS “Water Regulations Advisory Scheme” The “Water Regulations Guide” contains all the Regulations and Guidance (Replaces Water Supply Byelaws Guide) copyright 2006

Schedule 1 – Fluid Category Risk Comparison
July 2005 Previous UK Classification European/New UK Classification Backflow Prevention Examples (Used in Building Services) Class 1 Schedule A Risk European Fluid Category 5 Air Gap – AA AB Pipe Interrupter - DC European Fluid Category 4 RPZ – BA Pipe Interrupter - DB Class 2 Schedule B Risk European Fluid Category 3 Double Check – ED Class 3 Schedule C Risk European Fluid Category 2 Single Check – EB Wholesome Water European Fluid Category 1 No Protection Required (Except Secondary, at times) copyright 2006

Application of Regulations
July 2005 2. - (1) Subject to the following provisions of this regulation, these Regulations apply to any water fitting installed or used, or to be installed or used, in premises to which water is or is to be supplied by a water undertaker. (4) Nothing in these Regulations shall require any person to remove, replace, alter, disconnect or cease to use any water fitting which was lawfully installed or used, or capable of being used, before 1st July 1999. “lawfully” means conformance to the Water Byelaws copyright 2006

Regulation 2 Retrospective Clause
July 2005 Example of New Water Regulations applying to existing installations R15.21 “While the Regulations are not retrospective appropriate measures must be taken against any known situation where there is a potential backflow risk from hoses. The offence will be deemed to have been committed when the hose was attached and not when the tap was first installed.” The same applies to filling loops etc. copyright 2006

Restriction on installation etc. of water fittings
Regulation 3 Restriction on installation etc. of water fittings July 2005 3. - (1) No person shall - (a) instal a water fitting to convey or receive water supplied by a water undertaker, or alter, disconnect or use such a water fitting; or (b) cause or permit such a water fitting to be installed, altered, disconnected or used in such a manner that it causes or is likely to cause - (i) waste, misuse, undue consumption or contamination of water supplied by a water undertaker; or (ii) the erroneous measurement of water supplied by a water undertaker. copyright 2006

What is Backflow? July 2005 “Backflow” means flow upstream, that is in a direction contrary to the intended normal direction of flow, within or from a water fitting. Back Siphonage (Vacuum on supply) Back Pressure (Downstream pressure higher than supply) Some devices are suitable for Back Siphonage only - e.g. DC Pipe Interrupter. Others e.g. BA (RPZ Valve) are suitable for both. copyright 2006

Backflow Example – Hotel Baths
July 2005 Negative pressure – could suck fluid out of bath via shower hose Solution – Secondary Protection Branch Valve Double Check Valve Model BRV Solution - Point of Use Protection Shower Hose Double Check Valve Model ED235 Supply pressure lost – mains or booster failure Tap turned on – Contaminated! copyright 2006

Secondary Backflow Protection
July 2005 Servicing Valves, Double Check and Drain Taps should be fitted to every branch (G11.3, G11.4, G11.5, G15.24, R ) copyright 2006

Branch Valve July 2005 Servicing Valve, Double Check and Drain Tap should be fitted to every branch (G11.3, G11.4, G11.5, G15.24, R ) Model BRPRV Servicing, Pressure Reducing, Double Check & Drain Tap Model BRV Servicing, Double Check & Drain Tap with Solder Unions copyright 2006

Point of Use Protection - The Law
July 2005 Backflow prevention devices MUST be fitted at POINTS OF USE - paragraph 15 (1) of the Statutory Instruments (Water Regulations). 15. (1) “Subject to the following provisions of this paragraph, every water system shall contain an adequate device or devices for preventing backflow of fluid from any appliance, fitting or process from occurring”. (3) “The device used to prevent backflow shall be appropriate to the highest applicable fluid category to which the fitting is subject downstream before the next such device”. G15.25 “The provision of zone or whole-site backflow protection should be in addition to individual requirements at points of use and within the system”. 3) The device used to prevent backflow shall be appropriate to the highest applicable fluid category to which the fitting is subject downstream before the next such device. copyright 2006

Whole Site Protection Example of “Whole Site Protection” - Florida USA
July 2005 Example of “Whole Site Protection” - Florida USA (Frost Protection unnecessary!) copyright 2006

Point of Use Protection
July 2005 Where the appliances are of different types, e.g. a Washing Machine and Dishwasher (commercial use), each appliance must have its own Backflow Protection - RPZ Valve Assembly - (Water Regulations Schedule 2, Paragraph 15) Point of Use Protection Point of Use Protection Built-in Category 3 protection – too low Built-in Category 3 protection – too low Prevents Cross Contamination copyright 2006

Cross Contamination Possible
Zone Protection July 2005 Where several appliances of the same type and same Fluid Category are used within a commercial building, Water Suppliers may accept a single RPZ Valve to protect multiple appliances. Zone Protection Cross Contamination Possible copyright 2006

Backflow Example “Wholesome” Water Fluid Category 1
July 2005 “Wholesome” Water Fluid Category 1 Solution - Single Check Valve at Branch Problem -Steel Pipe is Fluid Category 2 Risk E.g. Fire Sprinkler Cistern (with AA / AB air gap) Fluid Category 5 Model EB402 copyright 2006

Single Check Valve EB Single Check Valve Category 2 protection
July 2005 EB Single Check Valve Category 2 protection EB is “non-verifiable” meaning there are no test points provided. EA is verifiable but none is approved and since protection is still category 2, there is no benefit. Single Check Valve. To provide backflow protection from flexible hoses. Washing machine version pictured -(Model EB20FM235) No Tools Required Single Check Valve above DN50 are described as “Non-Return” but are currently acceptable for backflow protection. For double check valves, ensure upstream check valve cannot open downstream valve! Applications – Connections to steel pipe Prevent mixing of hot & cold (e.g. TMV) Fire sprinklers (no additives) copyright 2006

Double Check Valve ED Double Check Valve Category 3 protection
July 2005 ED Double Check Valve Category 3 protection ED is “non-verifiable” meaning there are no test points provided. EC is verifiable but none is approved and since protection is still Fluid Category 3, there is no benefit. Exceptionally low head-loss ED Device (with optional Drain Tap - Model ED132) Double Check Valve - model ED235. For fluid category 3 protection on shower hoses. Flow limiter option No Tools Required Applications – Supply to flats (whole site) Separate floors (secondary) Stainless Steel - exceptionally low head-loss – Model ED316 Numerous others copyright 2006

Double Check Valve – Low Loss
July 2005 E.g. Model ED132 - size 15 mm - has 1 m head loss compared with 4.5 m for conventional Double Check Valve at 3 m/s. copyright 2006

Pipe Interrupters DB Pipe Interrupter Category 4 protection
July 2005 DB Pipe Interrupter Category 4 protection There are many restrictions on its use - No control valves downstream 300 mm min. above spillover level or free discharge point Applications – Porous hoses for house only (Hose Union tap also requires a separate Double Check Valve) Model – DB20IL15 with quick release hose connector copyright 2006

Pipe Interrupters DC Pipe Interrupter Category 5 protection
July 2005 DC Pipe Interrupter Category 5 protection There are many restrictions on its use - Minimal restriction downstream 300 mm min. above spillover level or free discharge point 150 mm above sparge outlet Applications – Model DC257 Urinals (fed directly from supply pipe) copyright 2006

RPZ Valves – Category 4 Protection
July 2005 DN25 - DN32 DN15 - DN20 DN40 - DN50 DN65 - DN100 copyright 2006

RPZ (BA) Assembly in Cabinet
July 2005 Small cabinet (300 mm square) to house a 15 mm RPZ. E.g. for dishwashers etc. A large capacity fine strainer should be used for high volume applications Waterless Traps are ideal - conventional traps can dry out (check approved for application) RPZ Compact High performance copyright 2006

RPZ (BA) How it Works July 2005 Initial Connection With no pressure in the system, both Check Valves (1) and (2) are closed and the Relief Valve (3) is open. Once the upstream pressure (A) reaches about 0.3 bar, sufficient pressure exists above the Diaphragm (5) to compress the Spring (6) and close the Relief Valve (3). At approximately 0.5 bar, Check Valve (1) opens allowing water to flow into Zone (B). (Look at Check Valve (1)) Closed A further 0.1 bar is required to open Check Valve (2) and thereafter flow is maintained through the Valve. copyright 2006

RPZ (BA) How it Works July 2005 Initial Connection With no pressure in the system, both Check Valves (1) and (2) are closed and the Relief Valve (3) is open. Once the upstream pressure (A) reaches about 0.3 bar, sufficient pressure exists above the Diaphragm (5) to compress the Spring (6) and close the Relief Valve (3). At approximately 0.5 bar, Check Valve (1) opens allowing water to flow into Zone (B). A further 0.1 bar is required to open Check Valve (2) and thereafter flow is maintained through the Valve. copyright 2006

Downstream Pressure Increase
RPZ (BA) How it Works July 2005 Downstream Pressure Increase Backflow - due to an increase in downstream pressure - is prevented by Check Valve (2). Failsafe (Positive Action) If Check Valve (2) fails to seal whilst the downstream pressure (C) is higher than (B), the Relief Valve (3) will open before (B) gets to within 0.14 bar of the Supply Pressure (A). The Relief Valve (3) orifice is substantially larger than the open area of a leaking Check Valve and therefore prevents fluid reaching the base of Check Valve (1). copyright 2006

Installation Diagram July 2005 IGN Issue 3 requires RPZ installations to feature - Adequate Rear Clearance Tamperproof environment – Plant Room or use Cabinet Upstream Isolating Valve Downstream Isolating Valve Strainer RPZ Valve RPZ Valves must be annually tested Air Gap Access Height 0.3 m min 1.5 m max Discharge Pipe Ground / Floor / Cabinet copyright 2006

RPZ Typical Applications
July 2005 The Following MUST be protected with either an appropriate air gap or an RPZ assembly Sealed Heating Systems – Non house (Filling loops with Double Check Valve prohibited) Hose Union Taps - Commercial - (where Fluid Category 4) Clothes Washing Machines - Commercial use Dishwashers - Commercial use Cooling Coils - Commercial Under Floor Heating - Commercial Dyeing Equipment Printing and Photographic Equipment Pressurised Fire Fighting Systems Water Treatment Plant Vehicle Washing Plant Water Softening - not Salt copyright 2006

RPZ (BA) Guidance July 2005 RPZ’s have a pressure drop of about 0.6/0.7 bar inherent in their design. The supply pressure must be more than 0.7 bar. (The increase in pressure drop after 0.7 bar is small) Do not use an RPZ - On the inlet to a pump - fit to outlet On gravity systems - unless at least 10 m head On elevated mains systems - e.g. second floor and above RPZ Valves (BA device) need to be tested by an Accredited Tester after installation and annually thereafter . copyright 2006

Break Tank – with AB Air Gap AB Air Gap Category 5 protection
July 2005 AB Air Gap Category 5 protection Air Gap AB Either gravity supply from storage cistern or Boost with pumps Applications – “Non-Domestic” Hose Union taps e.g. Waste Bin Washing Wash-down Irrigation Laboratories Rain water Baths/Showers - Healthcare Bed pan washers “Boost-A-Break” Variable speed “Boost-A-Break” Fixed speed Break tank and Booster - model BTABV copyright 2006

Break Tank – with AF Air Gap AF Air Gap Category 4 protection
July 2005 AF Air Gap Category 4 protection Applications – Boosts pressure for high buildings where the mains supply is inadequate e.g. penthouse suites “Pent-A-Boost” Fixed speed Compact Domestic Booster - model BTAFV “Pent-A-Boost” Variable speed copyright 2006

Break Tank Accessories
July 2005 Wall cover Note – brackets required Outdoor GRP Kiosk with thermostatically controlled heater for break tank (model BTABV). Note - low level screened Type AB slot Drip Tray Applications – RPZ Valves, Break Tanks and other fittings must be protected from freezing Wash-down Irrigation copyright 2006

Filling Heating Systems – Category 3
July 2005 A CA device (with pressure control) can be used to automatically fill house and non-house heating systems less than 45 KW output. Unlike BA (RPZ) valves, CA devices do not need to be tested. A discharge pipe is required to be connected to the tundish. Filling Valve - CA device with PRV, strainer and servicing valves Model – CA296PRV copyright 2006

Filling Heating Systems – Category 4 Wall mounting brackets available
July 2005 R24.2 “The type of backflow protection device required should be suitable for Fluid Category 3 in the case of a house or for Fluid Category 4 risk for installations in premises other than a house”. (Water Industry now accept systems less than 45 KW output as Fluid Category 3) Quick-fill loops (with Double Check valve) are prohibited for “other than house” applications. Fill and pressurise with Autofill supply from - Mains – ground (& first floor) Boosted CWS Autofill is a Fluid Category 4 device for filling and pressurising Wall mounting brackets available copyright 2006

Heating System Accessories
July 2005 Unvented heating systems require a correctly sized & rated Expansion Vessel Model EVUP (10 bar) Approved for heating & domestic water Model EVCP (4 bar) Vessels must be correctly pre-charged Model BVEV Proper vessel valve – lock shield, wired, drain tap and union copyright 2006

Heating System Accessories
July 2005 Common accessories for commercial unvented systems include - Model WMV3 Water Meter – establish system volume and leaks Volumetric & readable to 1 litre Model ADR Air and Dirt Removers (separators) DN20 – DN250 Model DP5 Dosing Pots (3.5 – 25 litres) to add inhibitors – water meter helps determine system volume With anti-blowback and anti-scald copyright 2006

Requirements for water fittings etc.
Regulation 4 Requirements for water fittings etc. July 2005 4. - (1) Every water fitting shall - (a) be of an appropriate quality and standard; and (b) be suitable for the circumstances in which it is used. (2) For the purposes of this regulation, a water fitting is of an appropriate quality or standard only if - (a) it bears an appropriate CE marking in accordance with the Directive; (b) it conforms to an appropriate harmonized standard or European technical approval; (c) it conforms to an appropriate British Standard or some other national specification of an EEA State which provides an equivalent level of protection and performance; or (d) it conforms to a specification approved by the regulator. It is necessary to prove conformance – only use Water Regulations approved fittings. There are several organisations now - copyright 2006

Approval Organisations
Regulation 4 Approval Organisations July 2005 Available free on Internet Also available free on Internet Remember – to comply with Regulations, all fittings in contact with (wholesome) water supplied by the water company must be approved. copyright 2006

Regulation 4 - Compliance
July 2005 All fittings KIWA UK approved assure compliance with Regulation 4 – see their web site for approved products – copyright 2006

Regulation 5 Notification July 2005 5. - (1) Subject to paragraph (2), any person who proposes to install a water fitting in connection with any of the operations listed in the Table below - (a) shall give notice to the water undertaker that he proposes to begin work; (b) shall not begin that work without the consent of that undertaker which shall not be withheld unreasonably; and (c) shall comply with any conditions to which the undertaker's consent is subject. “Unreasonably” means 10 working days from receipt of application Water Companies are permitted to make “reasonable” terms and conditions copyright 2006

Regulation 5 continued Notification July 2005 1. The erection of a building or other structure, not being a pond or swimming pool. 2. The extension or alteration of a water system on any premises other than a house. 3. A material change of use of any premises. Notification is required for the following - There are others but these are for house installations. Everything requires notification in a “non-house” structure – see above (2) This regulation does not apply to the installation by an approved contractor of a water fitting falling within paragraph 2, 4(b) or 4(g) in the Table. Commercial alterations, bidet, RPZ Valve. copyright 2006

Contractor's Certificate
Regulation 6 Contractor's Certificate July 2005 6. - (1) Where a water fitting is installed, altered, connected or disconnected by an approved contractor, the contractor shall upon completion of the work furnish a signed certificate stating whether the water fitting complies with the requirements of these Regulations to the person who commissioned the work. (2) In the case of a fitting for which notice is required under regulation 5 (1), the contractor shall send a copy of the certificate to the water undertaker. copyright 2006

Water Conservation Automatic Flow Limiting Valve
July 2005 Automatic Flow Limiting Valve Combined Servicing Valve and Automatic Flow Limiting cartridge. Constant flow between 1 – 10 bar. 8 Colour-coded cartridges available - with matching colour on disc that snaps into plug Automatic Flow Limiting Cartridges 0.07 – 0.43 Lt/s Applications – Every appliance 15 or 22 mm Cartridges can be changed though side port with pliers copyright 2006

Water Conservation “Equi-Flow” - Shower Flow Limiter
July 2005 WITHOUT “Equi-Flow” - Shower Flow Limiter Insufficient flow Ensures even distribution of water in a controlled and balanced manner. Excessive flow New “Features & Benefits” sheet available WITH – Even distribution Model AFLE 1 bar Applications – 5 bar Showers in multiple occupancy buildings e.g. flats, hotels and student accommodation. 10 bar copyright 2006

Standpipe – Category 3 July 2005 ED Double Check Valve is required for Hose Union Taps used for “domestic purposes” Taps with integral check valves (HUK1) are no longer acceptable Miniature Standpipe – model SPTB. Only 250 mm high Applications – Above ground garden watering Offices, Schools, Recreation Ground Standpipe - Model SPED copyright 2006

Standpipe – Category 4 July 2005 “Non Domestic” Hose Union Taps may be risk assessed as Fluid Category 4 (G15.18) & a BA device could be used Hose and medium duty washdown gun Applications – Car Washing & Degreasing Plants Mini Irrigation Systems “Hand held hoses should be fitted with a self –closing mechanism at the outlet of the hose.” G15.17 Standpipe - Model SPBA copyright 2006

Standpipe – Installation
July 2005 Standpipe 750 mm MDPE Pile Insulation copyright 2006

“Conceal-A-Tap” Flush Hose Union Tap – vandal resistant, frost proof
July 2005 Flush Hose Union Tap – vandal resistant, frost proof New “Features & Benefits” sheet available Model - HUC copyright 2006

“Conceal-A-Tap” Suits any wall thickness – cut copper tube to suit
July 2005 Suits any wall thickness – cut copper tube to suit Model - HUC copyright 2006

Shown with optional hose guard and pipe cover
Tap Box July 2005 To prevent unauthorised use and prevent waste – use a lockable Tap Box. Available in rear entry or bottom entry. G11.5 warns against using spherical valves in frost prone areas. The Tap Box features a right angle pattern spherical valve, which does not have a trapped cavity and is therefore frost resistant. Tap Box - Model HUTB Applications – Wall mounted Hose Union Tap (Backflow prevention provided separately) Tap Box (surface entry)- Model HUTBS Shown with optional hose guard and pipe cover copyright 2006

Hose Union Tap Below Ground E.g. “Boost-A-Break” model BTABV
July 2005 Below ground hose union tap All irrigation outlets less than 150 mm above the ground are considered a Fluid Category 5 risk and must be fed via an AB or AUK1 air gap. E.g. “Boost-A-Break” model BTABV Model HUBG copyright 2006

Temperature Control July 2005 G18.5 “Terminal fittings or communal showers in schools or public buildings, and other facilities used by the public, should be supplied with water through thermostatic mixing valves so that the temperature of water discharged at the outlets does not exceed 43O C”. Supplied with AFL Servicing Valves fitted (including strainer) Copes with unbalanced pressures Applications – TMV Servicing Valve model BVTMV Wash basins Showers Baths Sinks Bidet Model TMV5213 Kit with AFL valves copyright 2006

Pressure Control July 2005 Model PRV535 Model PRV536 With Solder Unions to allow secure and neat connection to copper tube With Solder Unions and Servicing Valves Model PRVNGE Model PRV1300 Pilot Operated. Range of other controls - solenoid Exceptionally Low head loss copyright 2006

Regulations July 2005 7 Penalty for contravening Regulations 8 Modification of section 73 of the Act 9 Inspections, measurements and tests 10 Enforcement 11 Relaxation of requirements 12 Approval by the regulator or the water undertaker 13 Disputes 14 Revocation of the Byelaws copyright 2006

Resources – Specification Clauses
July 2005 Available at - Simply copy & paste into any project specification copyright 2006

Summary The salient points of this presentation are –
July 2005 The salient points of this presentation are – The Water Regulations Guide is the single most useful source of information The local water company has the authority to enforce, inspect and risk assess The Regulations apply to the whole building (if supplied by the water company) “Point of use” backflow protection is required – not whole site Communal bin washing – where a hose can be submerged – is Fluid Category 5 Irrigation outlets less than 150 mm above the ground are Fluid Category 5 The Fluid Category is dependant on the risk – not the fluid per sé Non House heating systems above 45 kW are Fluid Category 4 It is an offence to waste water – even if metered Water fittings must be approved – e.g. KIWA, WRAS, BSI copyright 2006

Thank You The End To view datasheets www.arrowvalves.co.uk
July 2005 Thank You To view datasheets Tel Fax copyright 2006

Primarily Focusing on Backflow Prevention

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