In order to eliminate hose twist under external torque and prevent these premature failures, Manuli Hydraulics recently introduced the Rotofit range of couplings. These couplings allow a direct connection of the hose termination on the port, eliminating the use of adaptors. Rotofit couplings also have a smaller sealing surface compared to standard fittings, which reduces the risks of leakage.
Rotofit couplings have been introduced on a number of mine sites and have considerably helped reduce equipment downtime due to premature hose failures.
For example, the introduction of Rotofit couplings on the hydraulic hoses between the distributor and the cylinder of the tipping system of Articulated Dumper Trucks eliminated the high torque stress that was generated on the hoses by the articulated system when in full steering condition. This resulted in an increase in the hose service life, in the machine performance, and reduced the cost of maintenance.
On a mine site in the Philippines, the ferrule/hose connection on the brake cooling lines of Dumper Trucks was causing premature hose failures due to torsional twisting of the hose assembly. Downtime due to these failures was costing the mine USD$ 18,000 per hour and per truck, with an average of one break down per month. Integrated Rotofit Code 61 flanges were installed on the brake cooling lines of four units. No failure of the brake cooling lines on these units was reported since these modifications were performed over three months ago.
Rotofit couplings have also been introduced on Dump Truck brake coolant circuits, which were plagued with two main application issues: very high temperatures (up to 135°C) and torsional stress on the hoses due to the motion of the wheel. Manuli Hydraulics customized its Rotofit coupling for this specific application, with special high temperature inner seals to withstand the extreme temperature environment, along with a 45° Code 61 termination end. The introduction of Rotofit couplings alleviated torsional stress with its live swivel features, and increased the hose service life by more than 200%.
For additional information on Rotofit couplings and how they can help you improve uptime on your mining equipment, please contact your country operations manager.
To download the Rotofit presentation, please click here: Rotofit Success Stories