- Current operating life of Dunlop belt
- Between 2 and 7 years. 2 years under the most severe conditions, up to 7 years for the more moderate conditions
- Average life of competitors belt
- Less than one year
Hot sulphur is pelletized from molten sulphur and the pellets come out from the pelletizing units in a wet condition. The water contains medium/low concentrations of sulphuric and sulphurous acid. Because Dunlop BV-VT belting is chemically resistant and sufficiently heat resistant under these conditions, it is providing a much longer operational lifetime. BV-VT also has good oil resistant and anti-static properties and complies with the required ISO 340 and/or MSHA flame retardant standards. BV-VT is also sulphur resistant. Sulphur is used for many rubber types as an accelerator in the vulcanising of rubber. Normal belts harden and start to crack after a short while under these conditions. When the covers of the belting start to crack, there will be problems with carry-back and carcass deterioration through penetrating acid (corrosion). Splice failures can also occur. Although BV-VT will eventually crack but only under the most severe conditions so the process is much slower than with ordinary belts. Under more moderate conditions, downstream in the material handling process and for stacking/reclaiming and ship-loading, there is no significant cracking in BV-VT so the belting is simply being replaced either when there is severe mechanical damage or when the top cover is worn out.
In one particular case, a steel cord belt was replaced within less than a year by a Dunlop Ferroflex BV-VT belt. The competitor’s belt had severely cracked after a short time and the metal carcass had started to corrode due to the presence of sulphuric acid. The Dunlop belt ran successfully for more than 5 years before being replaced due to wear with a new Ferroflex BV-VT belt.