11
Care must also be taken with the seal itself. The seal is not attached to the
tank; it is located into the fitting hole of the tank and stays in place because it
has a groove all around it. Make sure that each seal is securely in place
before you insert the vacuum tube. When the tube is inserted, it expands the
seal slightly, which presses it against the metal of the tank making it
watertight.
Fit the dust seal, a black/white, slightly dished ring seal supplied with the
tubes. The purpose of this is to exclude dust and dirt from the area around the
silicon seal. Note, this dust seal must be installed on the tube prior to
insertion, and then pushed up to the right position once the tube is fitted.
Aperture containing silicon seal
Fig 9
Fig 10
Dust seals
When inserting the glass tubes into the metal cradle, ensure the white plastic
cup is first located into position on the frame. The glass tube can then be slid
into place.
