An internal swaging system allows for mounting fittings to a hose without any contraction of the fitting flow diameter along its whole length. This method ensures full flow through the hose fitting – the same or close to the inner diameter of the hose. It requires special fittings (fittings and ferrules) and a special machine.
Here, a hardened, cone shaped swaging tool is used. Its diameter in the widest, working part is slightly bigger than the internal diameter of the fitting before crimping. The cone is pulled through the fitting so that it expands the fitting to the outside to obtain the expected diameter.
The fact that the flow rate is increased is the main advantage of the internal swaging method. It reduces loading/unloading time hence delivers substantial economic benefits. There is another advantage – the medium does not settle at the spot where the edge of the fitting hose tail meets the hose. This process is typical to traditional crimping methods. It is particularly important for the transfer of dry and loose or semi-liquid materials (granules, grain, cement, concrete, etc.) as well as foodstuffs.
The system is suitable for most rubber industrial hoses with diameters ranging from 2″ (DN50) to 12″ (DN300), hoses for water and air, fuels, petroleum products, industrial hoses transferring bulk solids, hoses for foodstuffs. The system is common for offshore hoses.
There are special fittings intended for the internal swaging. The range of typical fittings includes: fittings with BSP, BSPT, API/NPT male thread, weld-in fittings and flange fittings – made of carbon steel or AISI 316 stainless steel. The ferrules must be matched with two parameters: inner diameter and outer diameter of the hose.
Maximum working pressure is 20 bar (can be limited by the working pressure of the fitting connection).