Not sure what the pitot tube is made of, but I'm guessing either PVC or POM. ABS or diecast would be too likely to break.
From my understanding, the pitot tube is detachable, but it can also be left on the Valk and rotated 180º so that it is facing backwards under the nose. This way it can be kept on in Battroid mode, although there may be some interference with the T-Bar.
Graham