These Threaded tank Connectors are very useful for that awkward job.
These have a 1.5″ bsp, 2″ bsp and 110 mm threaded male with a plain solvent weld socket on the other end.
They can be used for putting drain off valves in filters or returns in to Quarantine tanks.
The 110 mm Threaded Tank connectors can be used for inlet/outlet ports between chambers.
If you take the nut off the 1.5″ 43mm tank connectors they can be used to screw in to the TMC UV 30 watt or TMC 55 watt Uv, they can also be used to screw in to the Electro Heaters or the Olympic Skimmer sockets.
These fittings are for solvent weld pipe.