Plumbing Connection 2-2015

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1 0 2 PLUMBING CONNECTION WINTER 2015
It was clear that PE-X provided the
most cost effective solution for the
small diameter roughin. Copper Press-
Fit provided the cheapest option for
use in DCW and DHW in the DN15-50
sizes. Using brazed copper plumbing
fittings for diameters greater than
DN50 whilst slower than using press-
fittings was found to be the most cost
effective due to their lower material
cost used in this estimate.
TIME IS MONEY
Many installations have time
constraints; however the ability to
allocate labour resources on to the
next project as quickly as possible
should also be a key consideration
in piping system selection. Figure 2
shows the installation time required
for a number of piping system
combinations.
The SX Estimate comparison study
found that the combination of using
PE-X for the rough in and Copper
Press-Fit for all sizes in DCW and
DHW plumbing provides the fastest
installation. In this estimate Copper
press-fit was found to be 14% faster
than using copper CTS fittings and
anecdotal market feedback is that
copper press-fit installations have
been found to be up to 30% faster than
CTS fittings.
SCOPING IT OUT
Cost is not the only factor when
selecting piping materials and care
needs to be taken to choose the
most appropriate material for the
environment where the plumbing
system is installed. Some things that
need to be considered include:
∫ The products you use should comply
with Australian Standards and
ideally be manufactured by a quality
endorsed manufacturer
∫ Use a reputable, proven quality
product with local support and
expertise.
∫ The correct tools for the job-many
systems require proprietary tools to
make a joint and these can add costs
or require new skills
∫ Solar hot water systems are
becoming more common with the
high temperatures experienced
within the industry and metallic pipe
systems are required in accordance
with AS3500.4. Pipe jointing
methods should be selected for the
temperature ratings of the fittings.
∫ Historic or sensitive buildings may
require flame free installations.
∫ UV stabilised materials should be
used when installed in areas of
direct sunlight & this can impact
choice between metallic pipes and
plastic pipes.
∫ Multi story buildings require higher
water pressures to get the water
to the top of the building and to
increase the pressure zones with
a building. The piping material/
pressure ratings are critical when
selecting a pipe system.
∫ Flow velocity within a pipe will
determine the pipe size to ensure
material longevity and prevent
system noise.
∫ Heated water circulating systems
require the pipe system material to
withstand the constant temperature
of the water without risk of failure.
The cost of plumbing is a significant
component of any building and this
analysis has shown that one piping/
fitting system may not be the best
selection for the specific sites
requirements.
As a summary the following pipe
systems will provide the most cost
effective total installation cost to the
plumber while ensuring a reliable and
proven installation.
1. Rough ins - PE-X
2. Domestic Cold Water – Copper
Press-Fit <50mm & CTS for >65mm
pipe sizes or Full CTS
3. Domestic Hot Water – Copper Press-
Fit <50mm & CTS for >65mm pipe
sizes or Full CTS
For further information on hydraulic
piping design considerations refer
to the recently published Hydraulic
Services Design Guide which is
downloadable free of charge at www.
. This is a 200 page
manual for use by hydraulic designers
and contractors.
COPPER CONNECTION
JOHN FENNELL
FIGURE 2
HOURS
INSTALLED TIME (HOURS)
-
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
PE-X Roughin
Cu PressFit
25-100mm
PE-X Roughin
Cu PressFit
< 50mm Cu
CTS>50mm
PE-X Roughin
Stainless
PressFit
25-100mm
PE-X Roughin
Cu PressFit
25-100mm
Full Cu
PressFit
15-100mm
Full Cu CTS
15-100mm
PE-X Roughin
PP-R (DCW)
Cu CTS (DHW)