Page 37 - Gi flipbook June/July 2018

The idea is similar to repairing a
punctured tyre by punching a nail TABLE 2: Materical decision matrix
through its surface and recoating the
torn tyre. The nail acts to instantly Weight ABS PP uPVC
block the leak while the recoating
process rebuilds the tyre's protective UV resistant 40% 2 1 4
layer. This new method can repair a Chemical resistant 40% 4 3 4
damaged riser instantly and
permanently, without suspension of Flexibility 10% 1 4 2
the gas supply. Cost 10% 3 5 3

THE SMART RISER JACKET’S Score 100% 2.8 2.2 3.7
COMPONENTS 1 - POOR 2 - BELOW AVERAGE 3 - AVERAGE 4 - GOOD 5 - EXCELLENT
The Smart Riser Jacket is composed of
materials with a high ultra-violet (UV)
and chemical resistance. They have a
long life and do not react chemically FIGURE 6: Design of Smart Riser Jacket
with one other.

Putty Stick
Putty Stick is a high-resistance
chemical used to temporarily seal
active gas leaks once the point of
leakage has been identified.

FIGURE 4: Putty stick

Unplasticised polyvinyl chloride riser. PP was the best choice in this
(uPVC) shell regard and uPVC was also considered
Plastics are less reactive with corrosive for this reason. ABS is too brittle and
chemicals compared to metal. To can easily crack under deformation.
create a protective shell for the Although PP was the cheapest
damaged pipe segment, three kinds of option, all three plastics were
Sealant plastic were considered: acrylonitrile affordable and comparatively lower in
The sealant is a sticky, gel-like butadiene styrene (ABS), price than using metal. By considering
substance created by mixing sealant polypropylene (PP), and uPVC. These UV and chemical resistance as the key
resin and hardener. It solidifies, were compared according to their selection criteria, the calculated score
completely sealing the cracked riser in physical and chemical properties, showed that uPVC was the best choice
few minutes. The material has high flexibility and cost. to produce the shell.
ultra-violet (UV) and chemical To increase the Smart Riser Jacket’s
resistance properties, which have been durability, it was essential that the Foam duct sealant
proven by laboratory tests. plastic shell had a high resistance to Foam duct sealant seals the gap
UV light and corrosive chemicals. uPVC between the shell and riser. The foam
has a high resistance to UV light and, becomes rigid on solidification. Its high
FIGURE 5: Sealant resin
although ABS and PP have comparable chemical and UV resistance provides
chemical resistance, these are less able further protection. Moreover, it
to prevent UV degradation. Latex paint prevents moisture infiltration and is
or anti-UV coating could be applied to easy to clean. There is a high adhesion
ABS and PP, boosting their UV factor between galvanized iron and the
resistance. However, the durability of sealant, so it bonds tightly with the
those methods is questionable. defective riser.
The flexibility of the material also
had to be considered as high levels of BENEFITS
flexibility would reduce installation Rapid riser maintenance with
problems. In order to fit the damaged continuous gas supply
location, the shell needed to easily Compared with riser replacement, the
deform for bends and branches on the Smart Riser Jacket can repair a gas riser

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