Why belt conveyors are not installed before shipping

Belt conveyor is actually divided into large belt conveyor and small belt conveyor, like small (of course, you can install the whole machine sent over, you can site directly use ~)
But what about large belt conveyors? The length of some dozens of meters, hundreds of meters, the height of some dozens of meters high, there is no way to ship the whole machine! (Should say not to say, even the transportation truck can not find, haha ~)
Although the belt conveyor is bulk shipment, but as long as the scope of reasonable transportation, and the cost is not high, it is possible to carry out the basic part of the installation, which also reduces the unchanged trouble brought about by the site guidance installation, such as finding small parts and other issues, but also to speed up the progress of the installation of the belt conveyor site.
In fact, regardless of whether the bulk or the whole machine shipment, on-site trial debugging still need to have the manufacturer in charge, so as to protect the stability of the subsequent use of the situation, but also less equipment itself some unnecessary problems to extend the service life of the belt conveyor.