... material deposited on the surface of the friction parts, the channel and the filter, caused a variety of machine failures, ... 30,000 = 450,000 kg = 450 tonsBesides: a variety of large-scale machinery, agricultural vehicles, water pumps, tractors, transformers and so on ... materials (all types of auto repair shop, a variety of large-scale machinery, ships, farm vehicles, farm machinery, pumps, tractors, ...