Backflow Special Interest Group Christchurch 24 September 2008

Backflow Prevention Practised by a few Understood by some Misunderstood by many Ignored by thousands!

The Great Divide n n Backflow requirements of the Water Supply Authority. Backflow requirements under the Building Code.

Supply Authority v Building Code requirements n n n A device at every boundary. An appropriate device installed at every identified source of a potential hazard. Issue is the reconciliation of conflicting requirements.

n n n Building Consents Standardisation of requirements Acceptable Solution Verification Method Alternative Solution Adopt AS/NZS 3500. 1 Water Services, in total? ?

n n n Building Consents Who is confused? ? ? ? ? The average tradesman wants a simple list of what to put where! Proactive to produce an “Advisory Note” for the use of all the industry. Adopt AS/NZS 3500. 1 in total? ?

n n n n Building Consents What about Devices not part of a Building/Compliance schedule: Pumping stations, Sports grounds, Parks and gardens, Water truck mounted devices, Marina’s? Boundary devices – who registers these and records that they are tested?

Compliance Schedules n n n Proactive audits on buildings that are late submitting their Warrant of Fitness? Carry out a Cross Connection survey during inspection? Acceptance of disclaimers on Form 12 A? Better to receive some documentation from an IQP than none at all!!

Domestic Fire Sprinklers n n A correctly designed “Combination” domestic fire sprinkler systems is not a backflow hazard. The specific intent of a “Combination” system is to have a domestic fixture connected to the sprinkler line, drawing-off water every time that fixture is used. n The sprinkler system and the domestic water system are thus one “Combined” system. n Please review a typical layout of a “Combination” system

25 = Most Hydraulically Disadvantaged Sprinklers Sprinkler 4 25 CU Sprinkler 3 32 25 Sprinkler 2 CU o e. L sp ing l i e nc CU 25 CU -9 . 0 m 0 l Domestic Supply 1 eil o Lo e ip m 5. 0 1 l/m CU 2 3. 40 0 11 C B 11 0. 4 0 E M l/m in Sprinkler 7 25 25 CU 49. 20 l/m Sprinkler 8 CU -3 . 0 m 49. 20 l/m NB. Sprinkler 8 & 9 are in the same room Sprinkler 9 A m PE nc MD in tre 0 5 e Pip Water meter and dual check Mains Tap-in & Ferrule F 40 c in p gs P 110. 40 l/m 1 h. /m e ac Sprinkler 1 m Sprinkler 6 11 0. 4 15 CU Pipe drop in Wall. 40 CU Pipe rise 4. 0 m in Wall. D Sprinkler 5 p m 3. 5 CU 40 Change pipe material at “D” U 12 l/m pi o /m 0 l C 25 m e ac Pip 32 CU 5. 0 -1 32 0. 4 11 = Less Hydraulically Disadvantaged Sprinklers Any number of domestic take-offs are permitted CU Length of pipe section “E” to “F” is 4. 0 m Typical “Combination” Domestic Fire Sprinkler System (NTS)

Domestic Fire Sprinklers • No backflow hazard exists in a correctly designed “Combination” domestic fire sprinkler system. • FIRE SPRINKELR SYSTEMS SAVE LIVES. • MAYBE YOUR LIFE! • Embrace the concept of “Combination” domestic fire sprinkler systems. • They do not use “more water” as has been stated!!

Domestic Fire Sprinklers • A “statement” endorsing the concept: “that correctly designed COMBINATION domestic fire sprinkler systems pose no backflow hazard” would be helpful in providing guidance to Designers, Territorial Authorities, Installers, NZ Fire Service and Consumers.

Challenges n n Education of the trade, Education of the general public, All the practitioners of the dark art of backflow prevention TALK to each other. Imported products? Dispensing faucet, water, soap and lotion. Steam ovens – testable double check?

Questions?

End Presentation Thank You