- Determine the position of the tie bars. If duct work is stiffened, position the tie bar at the intersection of the stiffeners.
- The overall length of the tie bar is equal to the clear internal duct dimensions. If the cross stiffening is external (as it can be found on positive pressure duct work), add 20 mm to the tube length. If the cross stiffening is internal (as it can be found on negative pressure duct work), deduct 20 mm from the tube length.
- The tube length is the tie bar overall length minus 2 mm. Hammer in the expanding plugs flush with both ends of the tube.
- Drill 7 mm Ø holes in the required locations.
- Fit the tie bar with one disc on the inside and one on the outside on each end of the tube. Tighten the screws with a 5 mm Allen key to expand the plugs.
- Crossing tie bars can be connected with a cross tie. Make sure that the tubes are straight before securing it. Then fasten the M8 screw tightly.