Straight bulkhead unions
Tube fittings
Straight bulkhead unions carry a tube run through a partition, a tank wall or a machine enclosure, held in place by a lock nut. This category covers 104 items for tube outside diameters from 6 L (M12x1.5) up to 42 L (M52x2).
The body carries a cutting ring port of equal size at each end, while a long bulkhead thread between them passes through the drilled hole in the panel. That bulkhead thread matches the port thread of each size, so M 16x1.5 goes on tube 10 L, M 52x2 on tube 38 S. Matching lock nuts ship as separate items.
Straight bulkhead unions go into tank walls, cabinet panels, machine covers, wherever a line has to cross a partition under pressure. The lock nut clamps the body from the far side, so pull loads plus bending loads from the piping pass into the sheet metal rather than into the tube joint. Large sizes up to 42 L (M52x2) take main lines through the wall, while 6 L along with 6 S handle gauge lines. Each pass through also forms a defined break point, letting one side come apart without touching the other.
