Pressure gauge to boiler pipe for L1(2012-16) and early LR (pre ambidextrous boiler)

This is the thinnest pipe on the boiler. This pipe is the long version that runs to the left side of the boiler when viewed from the perspective of operating the machine (on the ambidextrous version of the boiler this pipe is much shorter, perhaps just 10cm, as found on the later models of LR and the R24)