PROJECT
Gallagher’s water engineers calculated the
required water supply to Gallagher Estate, and
Graham Solomon, owner of plumbing contractor
Goldmark Plumbing, explains that this is a fairly
straightforward process: “It’s a factor of the
number of toilets and basins inside Gallagher.”
The convention centre’s existing 300 000ℓ water
system had been battling to provide sufficient
water supply to the centre during Johannesburg’s
periodic water cuts. With the additional 1mℓ the
venue will have a total of 1.3 million litres.
“In 22 years of being in the business it’s the first time
we’re doing a water storage system of this scale,” says
Solomon. At the time of Plumbing Africa’s site visit,
Goldmark had just installed temporary pipes to cater for
one of Gallagher’s major events over the weekend, the
iconic Comic Con Africa, due to concerns that its water
supply would be insufficient, says Solomon. He explains
that the new 1 million litres will not simply provide
emergency reserves but will be integrated to the main
water supply, with its water constantly circulating. “The
mains supplies the main water tank, and from there
joins the main line and on to the pre-existing tank. We
will be installing a water valve on the 160mm galvanised
water supply, whereby should there be a water leak it will
automatically switch itself off.” This component of the
job has not yet been done and will first pass through the
project engineers.
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The tank was manufactured by a company in Pinetown,
SBS, where it was prefabricated and shipped up to
Midrand to be assembled on site. “It consisted of sheets
of galvanised steel with a plastic curtain on the inside. It’s
very thick plastic – and that’s what holds the water in. The
steel sheeting is to stop the plastic from stretching out.
SBS’s website describes its tanks as follows: “The wall
panels and roof sheets of all SBS Tanks are made of
steel that is hot dipped and coated with a molten alloy of
55% aluminium, 43.5% zinc and 1.5% silicon, commonly
referred to by its trade name Zincalume , thus rendering
SBS Tanks highly resistant to corrosion.
“In some extreme cases, sacrificial magnesium anodes
are applied, further inhibiting potential corrosion. All SBS
Tanks are fitted with an approved liner which prevents
water coming into contact with the wall panels. This liner
complies with the Australian Water Quality Centre standard
AS/NZS 4020‐2005: Testing of Products for use in Contact
with Drinking Water.”
On a project of this calibre, says Solomon, all products
have to be SABS and Jaswic approved with a
manufacturer’s warranty on it; and be industrial strength so
as to handle the considerable pressure, traffic and harsh
outdoor conditions with regard to both pipes and valves,
so as to never restrict flow. “The actual SANS standards
are specified by the engineers on their drawings. While
on smaller jobs the plumber is often the wet services
One of the largest water supply systems of this type done in South Africa.
January 2020 Volume 25 I Number 11
www.plumbingafrica.co.za