Plumbing Connection Winter 2016

PLUMBING CONNECTION

WINTER 2016

SUCK IT UP

f you’ve ever used the restroom on a plane or boat you

would have noticed something a little out of the ordinary

with the toilet. That’s because they are fitted with

vacuum toilets rather than the traditional toilets you have

become accustomed to installing in the built environment.

Rather than a rapid influx and swirl of water, vacuum toilets

use the combined energies of vacuum pressure and gravity

for the collection, conveyance and disposal of waste through

a piping network that can be routed above ground. Vacuum

drainage systems consist of three main components: a

vacuum generating station, a conveyance system and

individual collection points.

Toilets are connected to a vacuum piping network via a

normally closed vacuum interface valve, which acts as a

point of separation between constant vacuum pressure in

the waste piping network and atmospheric pressure at the

toilet bowl. When the flush valve is activated, the controller

opens the interface valve. The pressure differential causes

air to enter the toilet bowl and pull the waste through the

fixture outlet before transporting it into the piping network,

routing it to the vacuum centre. The controller also activates

the flush water valve for rinse and re-fill of the bowl. The

opening and closing of the interface valve is precisely

controlled so that all waste is completely removed from the

bowl. A flush is completed using less than a litre of water and

any odours or bacteria are removed from the bowl.

Vacuum drainage technology is not new and untested by

any means and made its name in marine and aeronautical

industries in the 1960s. These specific industries had a

direct cost involved with carrying large volumes of water

for flushing and waste water so an alternative method was

required.

Around the same time vacuum technology started to be

used by sewage utility companies on land to take sewage

from pits of which one or more homes with traditional

drainage might drain to.

Sylvania waters in Sydney is an early example, where the

topography (flat reclaimed land on the coast with high water

table) made traditional drainage very expensive and near

impossible. It moved inside Australian buildings in the early

1990s with a specific need in the correctional and retail

building market.

For a number of years now several companies have been

providing vacuum systems in Australia; however they

VACUUM TOILET TECHNOLOGY HAS BEEN AROUND FOR DECADES, BUT UNTIL RECENTLY HAS MOSTLY BEEN

CONFINED TO USE IN PLANES, BOATS AND CORRECTIONAL FACILITIES IN AUSTRALIA DUE TO A LACK OF

STANDARDS AND CODES PERTAINING TO THEIR INSTALLATION. NOW THAT THIS HAS CHANGED IN 2016, THE

VACUUM TOILET MARKET IS TIPPED FOR A BRIGHT FUTURE.

JUSTIN FELIX

REPORTS.

Vacuum toilets use the combined energies of vacuum

pressure and gravity for the collection of waste.

COVER STORY:

VACUUM TOILETS

haven’t been able take their products mainstream due to a

lack of a deemed-to-comply AS3500-type code. This also

meant vacuum toilets couldn’t achieve a WaterMark as there

was no code to test them against.

This, in turn, resulted in a degree of resistance toward

specifying vacuum solutions in the market, due primarily

to the conservative approach by many specifiers, who

wouldn’t accept them under the Plumbing Code of Australia’s

alternative solution for installation approval track. This in

itself is quite understandable once you consider the sizeable

investment required in such a building-wide hydraulic

system.