I want to replace the tap nozzle of my kitchen tap to use an water-saving aerator. I have bought one and tried to install it. However, it doesn't fit due to a plastic elbow inside my tap. I am wondering whether I could get rid of this elbow.
The aerator I bought has a convex plastic part (picture A, blue arrow) that protects the ball joint. When I try to mount the aerator, this ball joint protection hits a plastic elbow inside the tap hollow (picture B, yellow). The elbow is itself connected to a soft pipe (picture B, green). So there is a pipe inside the tap.
As far as I've understood/tested it, the pipe carries hot water, while the rest of the tap hollow is where cold water runs. It's the first time I see such "mechanism" (and the first time I'm living in the UK, as it may be correlated). The original nose (picture C) has two specific areas: the inner circle fitting the end of the elbow (same diameters: see red arrows in pictures B and C), and the outside - for hot and cold water, respectively.
Can I safely remove the black elbow (yellow arrow, in picture B) from the tap?
As it is the first time I see such "mechanism", I am not so sure about the do's and don't's of it and why it exists. I am notably think of health issues (hot water contaminating cold water?), as well as preventing future leaks.