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What is a Tap?
Clive Hawkes, Technical Manager, Kiwa
Quality Services Ltd, a company involved
within the certification and testing of water,
gas and building products, talks about the
testing of the humble tap.
Tap endurance rig.
established standards throughout the world that
have to be complied with. To ensure there is no
effect on water quality, however, rarely will you
find any recognition between countries for each
others national requirements, for these
materials, particularly within Europe.
This results in manufacturers having to select
materials that can satisfy many separate
requirements before considering mechanical
and physical properties of a material to satisfy
the exacting mechanical testing requirements.
Satisfying mechanical requirements can be
slightly less onerous than the material
requirements because of European
Standardisation for Sanitary Tapware.
In general, compliance with an EN standard for
mechanical and performance requirements of a
tap, will be accepted in all member states of
Europe, with some tests being more relevant in
certain countries, such as acoustic and flow
rate requirements. Although there are some
variations depending on the product type, the
product will be subject to various endurance
tests of the vital mechanisms – 200,000 cycles
of the on/off control, 80,000 cycles of the swivel
The extensive testing equipment used within the laboratory.
spout and 30,000 operating cycles of diverter.
In addition there will be pressure testing,
o the public it would be a piece of possible effects on the water quality, because of dimensional and flow rate requirements.
brass which allows hot and cold the lead content. The lead content is a vital In the UK, these requirements are covered by
water into a kitchen sink, basin or constituent in the manufacturing process the Water Supply (Water Fittings) Regulations
bath. However, they would not be because it assists the machining of the brass, 1999, which do not make specific reference to
Taware of the engineering and so getting the balance correct between health these standards, however, allowing for minor
design which is required for a product to effects and manufacturing is important. variations these test are the same.
comply with various standards. Some manufacturers have introduced a Increasing attention has to be made to the
Manufacturers have to commit to a significant chemical washing process of the brass to flow rate requirements which can vary from
budget to ensure that the design of a product remove the lead residue from the surface of the country to country. Although this is not a
not only meets the basic requirement to operate brass which remains after the machining regulatory demand in the U.K, traditional
satisfactorily and look good, but also comply process. This was, and still is, the solution for plumbing systems are low pressure and
with the various different regulations and many manufacturers to the stringent water therefore will require taps with low resistance to
standards around the world, not just in the UK quality regulations in the USA. For other function properly, these therefore will not be
or each other country in Europe. countries, dezincification resistant brass will suitable for some European designed taps,
When considering a basic tap, each part has have to be used. Dezincification is a process which are designed for a minimum pressure of
to be assessed individually to see how much where the zinc content is removed from the 0.5bar. Some product standards such as
time, effort and cost is required. Particular brass. When in contact with certain types of BS5412 & EN1287 specifically refer to low
attention is needed when selecting materials. aggressive water, this can effect the structural pressure requirements, and taps have to
The tap body is the main constituent in properties of the brass. operate with a pressure as low as 0.1 bar,
contact with the water and therefore has many When we consider other non metallic so manufacturers have to consider if their
considerations. Although you will expect brass components within a tap, such as rubbers, products are suitable for high or low pressure,
to be used, the composition of the grade has plastics, ceramics and greases, there are or even both.
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