Unusual Ceramic Cartridge

[StuG]

Please can anyone tell me if they either recognise the manufacturer of the kitchen monobloc (see attached photo 1), or if they know how to remove the cartridge in the second photo and what tools to use. The spindle has a clip around it inside the hexagonal recess, but it is proving difficult to pull out. It looks like the outer ring with the 'hex' hole should be unscrewed and removed first.

Any help would be appreciated as the tap has developed an increasing drip!

 

[ShaunCorbs]

@YorkshireDave

 

[Welder]

Thanks Shaun 😱
Blimey! This is a new one even for me...
Looking at it closely, it looks entirely stainless steel so, I suspect, these are 25mm monoblock cartridges rather than traditional BS5412 style 1/2" or 3/4" types.
Much as it hurts, my advice is - new tap 🙁

 

[snowhead]

I'd say the piece with the hex inner is a screwed locking collar.
They'll be a special tool.

However a box spanner with the outer dimensions the same as the inner on the collar might undo it.
It's quite possible the cartridge is unique to the manufacturer.

 

[Ric2013]

My old car had a hexagonal driver for the oil sump plug. It wasn't hollow, mind, so even if you get one of the right dimensions from a motor factor, you'd need to drill the centre out, but perhaps they exist with holes. Probably easier to make one from an oversize bolt with two nuts locked against one another on the thread, or from a radiator valve key?
Or would a very large security Torx bit work?
Feel like an amateur engineering project? Or 'just buy the special tool from the manufacturer' but you don't know who that is 🙁
Then 'all' you'd have to do is see if you can find suitable innards for the cartridge.

 

[StuG]

I'd say the piece with the hex inner is a screwed locking collar.
They'll be a special tool.

However a box spanner with the outer dimensions the same as the inner on the collar might undo it.
It's quite possible the cartridge is unique to the manufacturer.

Thanks. That is what I thought, but so far I haven't managed to find a box spanner with the right dimensions. Rather frustrating.