8/3/2019 5.01 Cold Water Pipe Sizing Testing and Commissioning
2
1/3
T: 1300 815 127
www.pic.vic.gov.au
PO Box 536
Melbourne
Victoria, Australia 3001
Goods Shed North
733 Bourke Street
Docklands, Victoria 3008
5: COLD WATER PLUMBING
COLD WATER PIPE sIzING, TEsTING AND COMMIssIONING
TECHNICAL sOLUTION 5.01
Page 1
AIM
The aim of this technical solution is to clarify therequirements
for sizing, testing and commissioning acold water plumbing
installation.
PLUMBING REGULATIONs 2008
The Pin C f Asraia (PCA) is adopted byand forms part of the Pin
Rains 2008. PartB1 of the PCA species the objectives and
performancerequirements related to the installation of cold
waterservices.AS/NZS 3500.1: Pin an raina Par 1:War srvics, is a
deemed to satisfy document listed
in Part B1 of the PCA and contains sections on Sizingof water
services and Testing and Commissioning.
CERTIfyING A COLD WATER PLUMBINGINsTALLATION
There is an increasing variety of materials and productsfor the
supply of cold (and heated) water. It is particularlyimportant when
using unfamiliar products to ensure thatpipe sizing will be correct
for adequate performance ofthe installation.
There are two ways that an installation may be certiedas
complying:
1. PCA - The purpose of this provision is to enableexibility to
achieve an installation outcome thatmay not strictly comply
withAS/NZS 3500.1 but willproduce an equivalent performing
result.
2. AS/NZS 3500.1 - Generally, it is expected thatplumbing work
will be certied toAS/NZS 3500.1. Inthis case, your work must comply
withAS/NZS 3500.1 and would meet the PCA performance
requirements.
If you are certifying a water supply installation toAS/NZS3500.1
Water Services, it is important to understandhow to size the
system, and then select the correct pipe
sizes for different pipe materials.
ExAMPLE
This example (see Figure 1) follows the method of sizinga
typical installation in accordance withAS/NZS 3500.1 .You will need
to know the following:
> The Inde length.The length in metres from the water meter
to themost distant outlet. In this case to the back hosetap. In
this case 35m.
> The height in metre.
The height in metres (above the water meter) ofthe highest
outlet. In this case 3m.
> The preure available at the outlet.
> The available preure.
> flow rate and loading unit.
sTEPs
1. sketch the intallation.
The sketch should include the xtures and their loadingunits and
pipe sections identied by lettering as per
example in Figure 2.
2. Determine Available Preure:
Measure static pressure at meter = 720 kPa
Allow 67% of 720 kPa to represent a minimum pressure= 482.4 kPa
or 48.24m head
3. Determine Preure Drop:
The following formula is used to calculate the pressuredrop
along the index length.
P.D. = Hm Hs Hx
Where Hm = minimum available head in
metres = In his cas 48Hs = height of the heighest outlet
= In his cas 3
Hx = minimum head required at anyoutlet
= In his cas 5
Therefore:
P.D. = Hm Hs Hx
P.D. = 48 3 5
= 40m head
AS/NZS 3500.1 (Clause 3.3.2) requires a pressureof 50kPa (5m
head) at the most disadvantagedoutlet. In this case the back hose
tap requires aminimum of 50kPa pressure at a ow rate of 0.20L/s(ow
rate from Table 3.1).
If the water authority will specify a minimum pressureavailable,
use that gure. Alternatively, you cancheck the available pressure
at the meter and use67% of the reading to simulate minimum
pressureconditions. In this case pressure at the meter is
measured at 720kPa.
AS/NZS 3500.1 Table 3.1 species ow rates andloading units of
xtures and appliances.
8/3/2019 5.01 Cold Water Pipe Sizing Testing and Commissioning
2
3/3
T: 1300 815 127
www.pic.vic.gov.au
PO Box 536
Melbourne
Victoria, Australia 3001
Goods Shed North
733 Bourke Street
Docklands, Victoria 3008
5: COLD WATER PLUMBING
COLD WATER PIPE sIzING, TEsTING AND COMMIssIONING
TECHNICAL sOLUTION 5.01
Page 3
FIguRe 4 - teStINg PRoCeduRe
Water service/rst x/rough in completed
Isolated/disconnect any xtures or appliances that may bedamaged
by a high test pressure
Connect test bucket at a convenient point to enable testing of
piping(both hot and cold if required)
Cap all open ends
Fill system with water
Isolate water main if connected to mains supply
Pressure test system to 1500kPa with test bucketfor not less
than 30 minutes
Does pressure hold at 1500 kPa?
Yes
Locate and repair leak/s
Retest at 1500 kPa for 30 minutes
If possible ensure the water service is charged at mains
pressure duringconcealment prior to commissioning. Note: smaller
services may require regular
ushing to elimate problems caused by dead water over a long
period.
Is service DN80 or larger or supplied from a storage tank?
No
Yes
After t off ush each outlet(0.75m/s velocity) to remove
dirty
water and debris
No
Service/tank to be ushed anddisinfected as per Appendix G
and/or H AS/NZS 3500 1.2
COMMIssIONINGWhen the water service has been completed, check
the operation of all taps,
valves, cisterns, etc., to conrm their correct performance.
