Festo Tooltechnic (now Festool) have random orbit air sanders that use a single connection. Air down the centre tube, exhaust air round that and then the dust extraction around that.
Hellishly expensive but used by the trade in the UK years ago.
Just searched and still have air tools :-
Air Random Orbital Sanders - Festool Australia
Make sure you're sitting down when you get a price !
I used to work for the pneumatic division and even with a 35% staff discount they were expensive.
Colin
'56 Series 1 with homemade welder
'65 Series IIa Dormobile
'70 SIIa GS
'76 SIII 88" (Isuzu C240)
'81 SIII FFR
'95 Defender Tanami
Motorcycles :-
Vincent Rapide, Panther M100, Norton BIG4, Electra & Navigator, Matchless G80C, Suzuki SV650
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