This is a flexible
tube assembly. They are made specifically to connect petrol bowsers
to the outlet pipes of underground fuel storage tanks.
The
flexible nature of these assemblies allows for misalignment between
the bowser and the outlet flange. This characteristic also isolates
the joints in the fuel lines from vibrations generated by the pump
motors.
The
concertina form of the tube combined with it’s flexibility is a
safety feature by which the tube can stretch to over three and a
half times it’s original length without rupturing. This is to
prevent fuel spillage and possible fire in the event of a collision
between a vehicle and the bowser or when a motorist tries to drive
away without hanging up the fuel nozzle.
John Mills
& Associates perfected the automated process of joining the
stainless steel tube (wall thickness - two hundred and fifty
microns) to mild steel and cast iron flanges of five and twelve
millimetres in thickness. The process uses bare stainless steel
welding wire with an argon/helium/ hydrogen/carbon dioxide
shielding gas.
