150 - Internal Expanding Joint.
A straight fitting for joining tubes of the same size.
This fitting can only be used for 3.25mm wall thickness tube (1”, 1 1/4” & 1 1/2” BS EN 10255, formerly BS 1387, medium weight) and must not be used as a load bearing joint, particularly for tensile loads.
Type 149, which has superior load characteristics, may sometimes be used as an alternative.