Height adjustable plastic hydrant, has upper part movable up or down by overcoming pressure interaction between upper and lower parts

摘要

A pressure interaction (9) occurs between the upper and lower parts (2, 3) of the hydrant (1) and this pressure has to be overcome in order to move the upper part (2) relative to the lower part (3) when altering hydrant height. - The upper part is housed inside the lower part and can be fixed at a given height (8) inside the lower part.