I'd like to remove the L-shaped elbow that appears in the figure below.
I'm able to twist by hand only the lower of the two rings locking the L-shaped elbow in place.
- Is it safe to seek a tool to disassemble with a bit more torque?
- What is the name of this black ring and/or the tool that would be used to turn it. Notice there are two extra-large projecting tabs that would be broken if an ordinary wrench is used to grip.
I'm assuming that the sluggishness is due to blockage in this (left) side since there are two sides and the flow in the other side is swift.