A sealed connection device configured to connect a pump head with a pump on an additive pump. The sealed connection device may comprise an adapter and a sealing collar that inserts into the adapter. The sealing collar may comprise a body with a bore forming open ends, a shoulder disposed between the open ends, an annular detent adjacent the shoulder, annular grooves, one being disposed on the shoulder two others found on either side of the shoulder, and o-rings disposed in the annular grooves. The pump may couple with a first side of the adapter, the pump comprising a shaft that inserts in the bore of the sealing collar. The pump head may insert into a second side of the adapter so as to contact one of o-rings on the sealing collar.