Brass Compression Tube Fittings

Brass compression fittings make the same demountable tube joint as their stainless counterparts, on copper, brass or soft steel tubing. Tightening the nut drives a tapered ferrule into a cone in the body; the ferrule closes on the tube outside diameter, seals against it and bites in enough to hold against pull-out. The joint can be broken and remade with spanners.

The range photographed covers straight unions, male and female connectors onto pipe thread, union elbows, union tees and union crosses, which is the set needed for gauge and instrument tubing, pneumatic control lines and low-pressure fluid runs.

Brass is chosen where cost and machinability matter more than corrosion resistance, and it is well suited to compressed air, water, and hydraulic and lubrication lines at moderate pressure. It should not be used with ammonia, which causes stress-corrosion cracking in copper alloys, and dezincification-resistant grades are called for in aggressive or chloride-bearing water. Where the medium is corrosive or the duty is hot, the stainless range is the correct alternative.

When ordering, state the tube outside diameter and wall thickness, whether the sizes are inch or metric, the configuration, and the thread form and size of any pipe-thread end. Confirm the ferrule count and the pressure rating with the supplier; neither is marked on the fittings photographed, and the working pressure of the joint follows the tube rather than the fitting.