www.arrowvalves.co.uk copyright 20061 primarily focusing on backflow prevention presentation by...
Post on 31-Mar-2015
231 Views
Preview:
TRANSCRIPT
www.arrowvalves.co.uk copyright 20061
Primarily Focusing on Backflow Prevention
Presentation By
Steve Grace B-Eng FIPHE
Technical Director - Arrow Valves Ltd
March 2006
References to the Water Regulations Guide with practical solutions
www.arrowvalves.co.uk copyright 20062
Objectives
Fluid Categories – risk classification - New UK standards Regulations 2 – 6 – requirements and solutionsBackflow – how it occurs, back siphonage vs back pressureBackflow prevention devices - Fluid Categories 2 – 5RPZ valves – use, installation & testingSealed heating – regulations and devicesWater Fittings Approval Standards – Kiwa, WRASWater conservation – requirements and devicesHose Union Taps - requirements and devicesTemperature – limit and controlSummary
www.arrowvalves.co.uk copyright 20063
The legal UK Water Regulations include -
Regulations & Guidance Available Information
The Water Supply (Water Fittings) Regulations – Statutory Instruments 1148
Schedule 1 – Fluid Categories
Schedule 2 – Requirements for Water Fittings
The “Water Regulations Guide” contains all the Regulations and Guidance(Replaces Water Supply Byelaws Guide)
Guidance is produced by DETR (DEFRA) and WRAS “Water Regulations Advisory Scheme”
www.arrowvalves.co.uk copyright 20064
Schedule 1 – Fluid Category Risk Comparison
European Fluid Category 5
European Fluid Category 4
European Fluid Category 3
EuropeanFluid Category 2
EuropeanFluid Category 1
Class 1Schedule A Risk
Class 2Schedule B Risk
Class 3Schedule C Risk
Previous UKClassification
European/New UKClassification
WholesomeWater
Air Gap – AA AB Pipe Interrupter - DC
RPZ – BAPipe Interrupter - DB
Double Check – ED
Single Check – EB
No Protection Required(Except Secondary, at times)
Backflow Prevention Examples(Used in Building Services)
www.arrowvalves.co.uk copyright 20065
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.
Regulation 2 Application of Regulations
“lawfully” means conformance to the Water Byelaws
www.arrowvalves.co.uk copyright 20066
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.”
Regulation 2 Retrospective Clause
The same applies to filling loops etc.
www.arrowvalves.co.uk copyright 20067
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.
Regulation 3 Restriction on installation etc. of water fittings
www.arrowvalves.co.uk copyright 20068
Back Siphonage
Courtesy of WRAS
This tap is sucking up water due to a vacuum in the supply pipeand an inadequate air gap.
www.arrowvalves.co.uk copyright 20069
What is Backflow?
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.
“Backflow” means flow upstream, that is in a direction contrary to the intended normal direction of flow, within or from a water fitting.
www.arrowvalves.co.uk copyright 200610
Backflow Example – Hotel Baths
Supply pressure lost –
mains or booster failure Tap turned on –
Negative pressure – could suck fluid
out of bath via shower hose
Contaminated!
Solution -Point of Use Protection
Shower Hose Double Check Valve
Model ED235
Solution – Secondary Protection
Branch ValveDouble Check Valve
Model BRV
www.arrowvalves.co.uk copyright 200611
Secondary Backflow Protection
Servicing Valves, Double Check and Drain Taps should be fitted to
every branch(G11.3, G11.4, G11.5,
G15.24, R15.24.1)
www.arrowvalves.co.uk copyright 200612
Branch ValveServicing Valve, Double Check and Drain Tap should be fitted to every branch
(G11.3, G11.4, G11.5, G15.24, R15.24.1)
Model BRVServicing, Double Check & Drain Tap
with Solder Unions
Model BRPRVServicing, Pressure Reducing,
Double Check & Drain Tap
www.arrowvalves.co.uk copyright 200613
Point of Use Protection - The LawBackflow 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.
www.arrowvalves.co.uk copyright 200614
Whole Site Protection
Example of “Whole Site Protection” - Florida USA(Frost Protection unnecessary!)
www.arrowvalves.co.uk copyright 200615
Point of Use ProtectionWhere 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 UseProtection
Prevents Cross Contamination
Point of UseProtection
Built-in Category 3 protection – too low
Built-in Category 3 protection – too low
www.arrowvalves.co.uk copyright 200616
Zone ProtectionWhere 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
www.arrowvalves.co.uk copyright 200617
Backflow Example
Problem -Steel Pipe
is Fluid Category
2 Risk
E.g. Fire Sprinkler Cistern
(with AA / AB air gap)
Solution -Single Check
Valve at Branch
“Wholesome” Water Fluid Category 1
Fluid Category 5
Model EB402
www.arrowvalves.co.uk copyright 200618
Single Check ValveEB Single Check ValveCategory 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.
Applications –
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!
Single Check Valve. To provide backflow protection from flexible
hoses. Washing machine version pictured -(Model EB20FM235)
No Tools Required
Connections to steel pipe
Prevent mixing of hot & cold (e.g. TMV)
Fire sprinklers (no additives)
www.arrowvalves.co.uk copyright 200619
Double Check ValveED 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.
Applications –
Exceptionally low head-loss ED Device (with optional Drain Tap - Model ED132)
Stainless Steel - exceptionally low head-loss – Model ED316
Double Check Valve - model ED235. For fluid category 3 protection on
shower hoses. Flow limiter option
No Tools Required
Supply to flats (whole site)
Separate floors (secondary)
Numerous others
www.arrowvalves.co.uk copyright 200620
Double Check Valve – Low Loss
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.
Head Loss / Flow Chart 15 mm DCV
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
Velocity (m/s)
Del
ta P
ress
ure
(m H
2O)
Conventional DN15
Arrow Valves ED132
www.arrowvalves.co.uk copyright 200621
Pipe Interrupters
DB Pipe InterrupterCategory 4 protection
There are many restrictions on its use -
No control valves downstream
300 mm min. above spillover level or free discharge point
Applications –
Model – DB20IL15with quick release hose connector
Porous hoses for house only(Hose Union tap also requires a separate Double Check Valve)
www.arrowvalves.co.uk copyright 200622
Pipe Interrupters
DC Pipe InterrupterCategory 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 –
PZ
R
Model DC257Urinals
(fed directly from supply pipe)
www.arrowvalves.co.uk copyright 200623
RPZ Valves – Category 4 Protection
DN15 - DN20 DN25 - DN32
DN40 - DN50
DN65 - DN100
www.arrowvalves.co.uk copyright 200624
RPZ (BA) Assembly in Cabinet
A large capacity fine strainer should be used for high
volume applications
Small cabinet (300 mm square) to house a 15 mm
RPZ. E.g. for dishwashers etc.
Waterless Traps are ideal -conventional traps can dry out(check approved for application)
RPZ
Compact
High performance
www.arrowvalves.co.uk copyright 200625
Initial Connection
RPZ (BA) How it Works
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))
A further 0.1 bar is required to open Check Valve (2) and thereafter flow is maintained through the Valve.
Closed
www.arrowvalves.co.uk copyright 200626
Initial Connection
RPZ (BA) How it Works
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.
www.arrowvalves.co.uk copyright 200627
Downstream Pressure Increase
RPZ (BA) How it Works
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).
Backflow - due to an increase in downstream pressure - is prevented by Check Valve (2).
Failsafe (Positive Action)
www.arrowvalves.co.uk copyright 200628
Installation Diagram
Ground / Floor / Cabinet
Access Height0.3 m min1.5 m max
Upstream Isolating
Valve
Downstream Isolating
Valve
Strainer
RPZ Valve
Air Gap
Discharge Pipe
IGN 9-03-02 Issue 3 requires RPZ installations to feature -
AdequateRear
Clearance
RPZ Valves must be annually
tested
Tamperproof environment – Plant Room or
use Cabinet
www.arrowvalves.co.uk copyright 200629
RPZ Typical Applications
· 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
The Following MUST be protected with either an appropriate air gap or an RPZ assembly
www.arrowvalves.co.uk copyright 200630
RPZ (BA) Guidance
· 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’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 -
RPZ Valves (BA device) need to be tested by an Accredited Tester after installation and annually thereafter .
www.arrowvalves.co.uk copyright 200631
Break Tank – with AB Air Gap
AB Air GapCategory 5 protection
Either gravity supply from storage cistern or
Boost with pumps
Applications –“Non-Domestic” Hose Union taps
e.g. Waste Bin WashingWash-down
IrrigationLaboratoriesRain water
Baths/Showers - HealthcareBed pan washers
Air Gap AB
“Boost-A-Break” Fixed speedBreak tank and Booster - model
BTABV
“Boost-A-Break”Variable speed
www.arrowvalves.co.uk copyright 200632
Break Tank – with AF Air Gap
AF Air GapCategory 4 protection
Applications –
“Pent-A-Boost” Fixed speedCompact Domestic Booster - model
BTAFV
“Pent-A-Boost”Variable speed
Boosts pressure for high buildings where the mains
supply is inadequate
e.g. penthouse suites
www.arrowvalves.co.uk copyright 200633
Break Tank Accessories
RPZ Valves, Break Tanks and other fittings must be protected from freezing
Outdoor GRP Kiosk with thermostatically controlled heater for break tank (model
BTABV). Note - low level screened Type AB slot
Applications –
Wall coverNote – brackets required
Wash-down
Irrigation
Drip Tray
www.arrowvalves.co.uk copyright 200634
Filling Heating Systems – Category 3
Unlike BA (RPZ) valves, CA devices do not need to be tested. A
discharge pipe is required to be connected to the tundish.
A CA device (with pressure control) can be used to automatically fill house and non-house heating systems less than 45 KW output.
Filling Valve - CA device with PRV, strainer and servicing valves
Model – CA296PRV
www.arrowvalves.co.uk copyright 200635
Filling Heating Systems – Category 4
Quick-fill loops (with Double Check valve) are prohibited for “other than house” applications.
Fill and pressurise with Autofillsupply from -
Mains – ground (& first floor)
Boosted CWS
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”.
Autofill is a Fluid Category 4 device for filling and pressurising
(Water Industry now accept systems less than 45 KW output as Fluid Category 3)
Wall mounting brackets available
www.arrowvalves.co.uk copyright 200636
Heating System AccessoriesUnvented heating systems require a correctly sized & rated
Expansion Vessel
Model EVCP (4 bar)Vessels must be correctly
pre-charged
Model EVUP (10 bar)Approved for heating & domestic water
Model BVEVProper vessel valve – lock shield,
wired, drain tap and union
www.arrowvalves.co.uk copyright 200637
Heating System AccessoriesCommon accessories for commercial unvented systems include -
Model WMV3Water Meter – establish
system volume and leaksVolumetric & readable to 1 litre
Model ADRAir and Dirt Removers
(separators) DN20 – DN250Model DP5Dosing Pots (3.5 – 25 litres) to add
inhibitors – water meter helps determine system volume
With anti-blowback and anti-scald
www.arrowvalves.co.uk copyright 200638
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.
Regulation 4 Requirements for water fittings etc.
It is necessary to prove conformance – only use Water Regulations approved fittings. There are several organisations now -
www.arrowvalves.co.uk copyright 200639
Regulation 4 Approval Organisations
Remember – to comply with Regulations, all fittings in contact with (wholesome) water supplied by the water company must be approved.
Available free on Internetwww.kiwa.co.uk
Also available free on Internetwww.wras.co.uk
www.arrowvalves.co.uk copyright 200640
Regulation 4 - Compliance www.kiwa.co.uk
All fittings KIWA UK approved assure
compliance with Regulation 4 – see their web site for
approved products –www.kiwa.co.uk
www.arrowvalves.co.uk copyright 200641
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.
Regulation 5Notification
Water Companies are permitted to make “reasonable” terms and conditions
“Unreasonably” means 10 working days from receipt of application
www.arrowvalves.co.uk copyright 200642
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.
Regulation 5 continuedNotification
Notification is required for the following -
(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.
There are others but these are for house installations. Everything requires notification in a “non-house” structure – see above
www.arrowvalves.co.uk copyright 200643
Regulation 6Contractor's Certificate
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.
www.arrowvalves.co.uk copyright 200644
Water Conservation
Automatic Flow Limiting Valve
Combined Servicing Valve and Automatic Flow Limiting cartridge. Constant flow between 1 – 10 bar.
Applications –
Cartridges can be changed though side port with pliers
8 Colour-coded cartridges available - with matching colour on disc that
snaps into plug
Automatic Flow Limiting Cartridges
0.07 – 0.43 Lt/s
Every appliance 15 or 22 mm
www.arrowvalves.co.uk copyright 200645
New “Features & Benefits” sheet
available
Water Conservation
“Equi-Flow” - Shower Flow Limiter
Ensures even distribution of water in a controlled and balanced
manner.
Model AFLE
Applications –
WITHOUT
WITH
Showers in multiple occupancy buildings e.g. flats, hotels and student
accommodation.
1 bar
5 bar
10 bar
Excessive flow
Insufficient flow
– Even distribution
www.arrowvalves.co.uk copyright 200646
Standpipe – Category 3
ED Double Check Valveis required for Hose Union Tapsused for “domestic purposes”
Taps with integral check valves (HUK1) are no longer acceptable
Applications –
Above ground garden wateringOffices, Schools, Recreation Ground
Standpipe - Model SPED
Miniature Standpipe – model SPTB.
Only 250 mm high
www.arrowvalves.co.uk copyright 200647
Standpipe – Category 4
“Non Domestic” Hose Union Taps may be risk assessed as Fluid Category 4
(G15.18) & a BA device could be used
Applications –
Standpipe - Model SPBA
Hose and medium duty washdown
gun
“Hand held hoses should be fitted with a self –closing mechanism at
the outlet of the hose.” G15.17
Car Washing & Degreasing Plants
Mini Irrigation Systems
www.arrowvalves.co.uk copyright 200648
Standpipe – Installation
750 mm
MDPE Pile
Standpipe
Insulation
www.arrowvalves.co.uk copyright 200649
“Conceal-A-Tap”
Flush Hose Union Tap – vandal resistant, frost proof
Model - HUC
New “Features & Benefits” sheet
available
www.arrowvalves.co.uk copyright 200650
“Conceal-A-Tap”Suits any wall thickness – cut copper tube to suit
Model - HUC
1. PARTIALLY INSERT SPECIAL KEY, ROTATE KEY ONLY 1/4 TURN, PULL DISC OUT.
2. CONNECT HOSE WITH "HOZELOCK" OR "INTER-LOCK" COUPLING (PULL BACK RING).3. PUSH KEY IN FULLY, TURN ON (1/4 TURN).
KIWA UK APPROVED A030526ARROW VALVES
T. 01442 823123 www.arrowvalves.co.uk
CONCEAL-A-TAP
www.arrowvalves.co.uk copyright 200651
Tap Box
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.
Applications –
Tap Box - Model HUTB
Tap Box (surface entry)- Model HUTBS
Shown with optional hose guard and pipe cover
Wall mounted Hose Union Tap(Backflow prevention provided
separately)
www.arrowvalves.co.uk copyright 200652
Hose Union Tap Below GroundBelow 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
www.arrowvalves.co.uk copyright 200653
Temperature Control
Supplied with AFL Servicing Valves fitted (including strainer)
Copes with unbalanced pressures
Applications –
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”.
Model TMV5213 Kit with AFL valves
TMV Servicing Valve model
BVTMV
Wash basins
Showers
Baths
Sinks
Bidet
www.arrowvalves.co.uk copyright 200654
Pressure Control
Model PRV535
With Solder Unions to allow secure and neat connection to copper tube
Model PRV536
With Solder Unions and Servicing Valves
Model PRVNGE
Pilot Operated. Range of other controls - solenoid
Model PRV1300
Exceptionally Low head loss
www.arrowvalves.co.uk copyright 200655
Regulations 7 - 14
• 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
www.arrowvalves.co.uk copyright 200656
Resources – Specification Clauses
Available at -
www.arrowvalves.co.uk
Simply copy & paste into any
project specification
www.arrowvalves.co.uk copyright 200657
Summary
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
www.arrowvalves.co.uk copyright 200658
The End
Thank You
To view datasheets
www.arrowvalves.co.ukinfo@arrowvalves.co.uk
Tel. 01442 823123Fax. 01442 823234
top related