Plumbing Connection 1-2015

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5 6 PLUMBING CONNECTION AUTUMN 2015
FLOW CONTROLLERS EXPLAINED
F low controllers, flow restriction devices, FRDs,
“annoying bits of plastic are said to muck up the
shower pressure”... Whatever you want to call them;
flow controllers have been a critical part of tap and shower
design for many years, particularly since the introduction of
the government initiated WELS (Water Efficiency Labelling and
Standards Scheme) in 2005.
Statistics provided on the WELS website (www.waterrating.
) suggest that by utilising more efficient products (in
both energy use and water use);
Australians could save more than
a billion dollars between now and
2021. Water efficient shower usage
alone is predicted to provide up
to one third of the water savings,
providing cost savings in the
delivery and removal (sewage) of
water.
Flow controllers provide the
obvious benefit of being able to
limit or control the overall flow of
water through a tap or shower. The
flow rate from an unrestricted tap
or shower (such as a bath spout)
in excess of 20 litres per minute
can be reduced to as low as 2-4
litres per minute for taps or 4.5-7
litres per minute for showers. In
some cases, the consumers may
not be happy with these reductions
and choose to remove the flow controllers. This is often
done without consideration of the other advantages of flow
controllers in the overall domestic water system.
Some of the flow controller’s additional capabilities include
the capacity to regulate pressure through a system. A flow
controller, when correctly designed into a shower for example
will ensure a constant flow rate of say 7 litres per minute,
across a wide range of pressures (typically between 150
and 350 kPa). This will ensure that changes in flow are not
experienced by the user (of the shower) when someone else in
the house turns on another tap or flushes a toilet.
The effects of removing flow controllers from plumbing
fixtures expands if you take a step back and look at it from a
broader perspective. Housing trends are showing an increase
in high density living in which could expose issues with the
capacity of our water infrastructure networks. Flow controllers
help to ensure that the local water pressure in the mains does
not reduce to levels below what engineers had intended.
Flow controllers are able to regulate water flow and water
pressure through a tap or shower by utilising a dynamic
O-ring (dynamic in that it is able to deform and change during
operation at different conditions) housed in a plastic body.
As the pressure at the flow controller increases (typically
resulting in an increase in flow for an unrestricted system),
the O-ring deforms outwards across the body. This reduces
the flow through the flow controller
due to the reduction in the fluid
waterway. The entire flow controller
assembly is usually about the size
of a 5c piece, and can be located
at a number of positions in a tap or
shower system – the location being
critical to the performance of the
flow controller in the product.
Some of the common faults
that occur with a flow controller
include blockage by debris (in
particular plumbers’ tape), loss
of performance due to extreme
conditions such as excessive
pressure (greater than 500 kPa)
and incorrect installation as they
only work properly in one direction.
Mechanical endurance testing
is conducted on all models of flow
controllers, meaning that when
used correctly, they are able to maintain performance for the
life of the product they are fitted to.
In terms of sourcing products with flow controllers, don’t be
tempted to remove these items to increase your flow rates.
Simply, choose what is right for your application. It is also
worth noting that some products are specifically designed and
engineered to operate at a given flow rate – the flow rate it is
supplied at. Most manufacturers also supply products, released
in varying star ratings to accommodate different consumers.
Choose what’s right for you, cost conscious or luxury?
Whichever product you choose, ensure that it is fitted with
a flow controller. It will always be better for your client’s back
pocket and the environment.
FRANK IAPOZZUTO SHEDS LIGHT ON FLOW CONTROLLERS AND DESCRIBES THE MYRIAD BENEFITS THESE CLEVER
LITTLE DEVICES POSSESS.
FLOW RESTRICTORS
Prove Standards & Engineering Pty Ltd.
THE INNERWORKINGS OF FLOW
RESTRICTORS
NO OR LOW
PRESSURE (O BAR)
POSITION 1
NORMAL PRESSURE
(3 BAR) POSITION 2
HIGH PRESSURE (5
BAR) POSITION 3