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PLUMBING CONNECTION
AUTUMN 2015 17
been avoided had the contractor undertaken the relevant
training and followed the manufacturer’s installation
procedures or guidelines. In a day and age when clients want
the job finished yesterday, it’s tempting to take shortcuts
or miss one of the small yet vital steps that would ensure a
successful installation.
Bob Le Hunt of Le Hunt Consulting Engineers who consults
on electrofusion projects, explains that the consequences of
failure can not only be costly but dangerous too.
“Sometimes these things will fail almost instantly but
unfortunately, they usually fail after concrete has been
poured over them. Occasionally an installer encounters a
leak during a pressure test before covering the pipes up.
In this instance they will fix it immediately. At other times,
there won’t be a leak and all seems in proper working
order. They backfill it and it might fail 12 months down the
track. As you can appreciate, it becomes a big job to shut
everything down, dig it up and replace the pipes and fittings.
If you’re working with gas, the consequences are taken to
another level. It could cause injury or even death to people.
“We went through all of our records over the past 30
years to try and come up with a histogram that depicted the
major causes of problems with electrofusion and we got to
about 95% of the causes that we had that we put down to
installation. Some were put down to faulty pipes, fittings and
machinery; however, there was an overwhelming and clear
showing for installer error,” Bob explains.
“A major problem stems from contractors who have
worked with smaller profile pipes who then jump onto
projects that involve much bigger pipes up to 100mm. They
apply all of the same procedures without taking into account
the fact that everything needs to be upsized and clamps
and calipers become a major necessity to ensure everything
is aligned prior to making the join. Low pressures become
high and the whole game changes, as should the procedures
involved. Unfortunately, in many cases, it does not.”
When there is a fire main involved it’s a matter of
regulation that a statutory fire test is conducted by a
certified tester. They test to around 1750kPa as a rule and
everything has to hold for a period of time without leaking.
This isn’t the case in other situations where only minor
testing such as an air test or low head water test is required.
Another major problem is a lack of training being
undertaken by contractors prior to accepting jobs. To put
T