Hey Prairie Dawg, “What about wear plate and details to keep in mind?”

Wear plate is found just about everywhere within the sand & gravel, heavy mining & quarrying industries. From your excavating equipment to basic conveyor hoppers, screen feed and discharge lips, to believe (it or not) right inside the crushing chamber of most crushers on the market to date — helping as secondary support to the high strength poured and patterned alloys necessary for the reduction process. Without manufacturers of this high strength specialty steel, and fabricators to design and install the plates, we couldn’t continue to operate these aggregate producing machines. They would only last days and maybe even hours if operating without this bulletproof protection.

There are many different types of wear plate to choose from and it is always best to do some applications research directly from the manufacturers or their local representation. Often times price dictates when it shouldn’t (using an inferior, less quality type of recipe design) and so often that is the wrong decision as the change out time costs are often the same for the best choice versus the lesser and if the lesser life has what it states as being having less hardness or abrasion resistance than I guess you will likely spend more in the long run changing it out more often.

This wear material like other moving parts still needs to be tracked regularly as in certain locations the rock and everything else associated may have higher abrasion characteristics which wear even the best sacrificial wear plate material out quickly. At minimum, weekly checks should be required throughout the entire plant. And it may become necessary to increase inspections when material is processed from different areas of the mining location, as the coarseness variations can quickly change these life cycles.

I often find it best to design wear plates for our clients that can be easily changed out by making them smaller and more focused to actual material contact flow patterns. Besides, who likes buying a plate that only ever gets one wear spot in it and you throw the rest in the scrap bin. Multiple plate zones with symmetrical bolt patterns are much welcomed revisions that can be made to most any factory built machine using single designed, large surface plates like those in screen feed boxes/chutes. By modifying these types of heavy wear locations it often allows rotational use along with working a worn plate out over a series of incoming new plates instantly providing increased life cycles, a win-win in my book.

Some wear plates are designed to add ultimate wear life and also provide an actual polished surface as it wears, which is intended to create a wear plate that no longer has sticking issues when working in colder, more moisture-driven climates. This plate is often referred to as an overlay plate and I personally think it is the Cadillac of long life cycle wear plate. There are many brand names out there and available to choose from and all seem to be in close pricing proximity so long as you have a provider nearby as freight/shipping can get a bit pricy on fairly large and heavy plates.

Here are some installation/fabrication attachment methods to consider when getting ready to replace the factory liner designed media:

  • Most AR (abrasion resistant) plate is fairly easy to process with manual torch or flame cutting and mainly CNC plasma to laser if available.
  • Holes are either square or round but can be slotted and slightly oversized if possible for easy fitting since nothing ever seems to be 100 percent perfect.
  • Some wear plates (even though extremely hard to achieve) are threaded and this is a really great style of connection design as the threads hold firm until the very end unlike the bolt head eventually wearing off if not protected with a blocking device or surround. These blocking devices or surrounds work really good unless the chute or hopper isn’t all that steep or rapidly flowing with material, as they will cause hanging material especially in corners.
  • With overlay plate the options become fairly limited as plasma cutting or water jet are the only real options for processing. As for as attachment, you can perimeter weld the base metal (mild steel) material with plug welds in larger sized pieces or you can oversize cut holes either square or round and weld nuts to create threaded plate options — like what would be found inside an impact crusher side plates. You can also weld in what we call a washer plate (usually 1/4″ or 3/8”) for good solid holding characteristics that allow for the bolt head to be flush with the top hardened overlay surface, keeping wear to the head of the bolt very minimized and lasting almost the entire life cycle of the plate.

Remember good quality, well planned-out wear plate media will keep you running and protecting the core of your high dollar equipment so don’t risk it by performing a quick inexpensive fix. One of my biggest pet peeves in the industry are those who run way beyond the life of the wear liner and destroy the good metal below, for no other reason than laziness or being too cheap to know better. In the long run this abuse of an operation only costs more the longer you leave it — in both time spent repairing and money it wouldn’t have taken if you are paying close attention and set better standards of operating equipment. A bandage wasn’t designed to last forever and usually falls off in the shower. Stay tuned in for more topics and details associated to come.

Questions? Tim Holmberg prairiedawg@pdpractical.com

 

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