Wear plate can be applied by methods including bolts, welding, or a combination of both.
Wear liners are commonly installed with countersunk bolts that provide smooth surfaces on the interior face of the skirtboard. These bolts also allow the simple replacement of the liner. Liners can be welded into position, with the obvious drawback being the difficulty in replacing worn liners. Should the installation require that the wear liner be welded into position, care must be taken to use the correct welding materials and techniques to match the liner material.
Wear liners reduce the escape of fugitive material from transfer points.
Another installation technique calls for the wear liner to be plug welded from outside the transfer point. With this technique, holes are drilled or cut through the plated steel wall. Then the back of the liner is welded to the chute wall. This system provides installation without bolt heads or holes protruding into the loading zone to act as targets for material abrasion. The liner provides its full thickness for wear-life. At the end of the liner’s life, replacement can be performed by cutting out the plug welds and installing new liners using the same holes.
When welding the liner into place, care must be taken to control the stress introduced into the lining metal. This type of installation can be seen as similar to applying wallpaper. If the edges are secured first, wallpaper tends to form bubbles in the middle. Abrasion-resistant plates will not form bubbles, but will develop residual stress if installed incorrectly. When the structure starts to flex under normal operation. These stresses can introduce cracks or even breaks in the wear liner.
Using proper welding techniques is the key to avoiding this potentially damaging stress. Standard practice uses an approach known as backstep or “back welding,” which uses stich welding along the top of the plate. At each weld, the bead is drawn back toward the welded end. In addition, workers must be careful to correctly select the type of welding rod to assure the strength and durability of the weld joint.
Finally, operators must consider the conveyor structure itself, ensuring that the chute wall and the surrounding support structures are strong enough to bear the added weight of any wear liners.
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