Inspect all clamping bars for corrosion and wear.
- Make sure bars are not warped or worn to the point that they cannot provide even, tight tension
Inspect all nuts and bolts.
- Replace all worn or stripped parts in the screen assembly
Maintain support deck.
- Remove channel rubber to inspect steel bars for wear, high and low spots for bar breakage
- Support area must be uniform to ensure an even and tight fit
Change Out channel rubber frequently.
- Changing channel rubber is recommended every time, or at least every other time, the screen is replaced
- Remember that channel rubber will wear from the bottom up, as well as from the top down. Check both sides
- Mixing channel rubber sizes or styles such as flat-top and round-top on the same deck will result in improper tensioning
Check cushion and spread of material feed.
- Cushioning of feed to the screen deck is essential to maximizing screen life. Use feed plates or stone boxes so that materials do not hit the wire cloth directly
- For maximum screen life and production, material should be spread out to feed evenly over the entire screening surface. This also reduces uneven equipment wear as the vibrator is operating in a more balanced condition
Inspect equipment for proper operation (balance and vibration).
- An unbalanced machine can cause premature wire cloth failure
- Equipment with a violent, uneven vibrating motion will cause stresses in the screen, causing premature failure of the screen cloth. The cloth may actually break apart
- Correct the unbalanced condition before continuing the screening operation
- Channel rubber or crown bar rubber must be replaced before new screens are installed to assure longer screen life.
- Screens should be centered on the deck before clamping rails are applied.
- Use new tension bolts and tension all bolts equally on both sides of the vibrator. All hole positions on clamping bars must be used.
- Make certain that butted screen panels are tight together and overlapping screens are properly installed to avoid oversized material leakage.
- Clamping rails must be exact length of the screen panel being installed. Never overlap clamping rails.
- After four to eight hours of operation, retighten the screen to take up any stretch that might occur.
- Worn clamping rails should be replaced to assure proper tensioning.
It pays to control your material screening costs by using proper screen installation and maintenance procedures. Unified Screening & Crushing helps by providing high-quality cloth, designed for your type of screening. By following these steps, you can dramatically increase the life of your screens, control costs and do a more efficient job of material screening.
Help us help you order the right wire cloth for your application.
Use the definitions and information on this page to determine the technical specs for your order. Of course, you can always discuss your specific application with a Unified wire cloth expert. Just call 866-968-3697.
Finished Panel Size
Flat screens without hooked edges: Simply measure the length and width of the screen in inches. Example: 48” wide and 72” long.
Flat screens with hooked edges: You need to determine the screen length and its OCW (outside clamping width) or ICW (inside clamping width) in inches. You can either:
- Check the OEM equipment manual, or •Measure an old screen, or
- If an old screen is not available, measure the clear width between the screen box plates and subtract 1-1/2” to determine the OCW.
Screen Length and Lapped Screens
When specifying screen length, always measure along the clamping edge and be sure to indicate any screen overlap, if required. Give the overall width first, then specify the length of the hook and the amount of screen overlap you need.
Example: 60” OCW x 96” long, 96” hook allowing for 2” lap (98” total length).
Lapped ends eliminate any leakage of oversized materials where screen sections meet. Normally, laps are 1” to 2” and are typically ordered with screens having an opening size of 1/4” or smaller.
When ordering screens with oblong openings, the slot direction must be specified in numerical terms. Note that Unified uses numerical terms when describing slot direction on your acknowledgments, packing slips and invoices. Also indicate the type of weave or number of shute wires (such as single shute or triple shute).
Examples of common slot direction phrases:
Note that these are for side tension screens. End tension screens will change slot direction terminology.
Special Fabricated Screens
Some shaker screens require special fabrication to meet all OEM specifications. Check your existing screens for the following features, and note them on your order:
- One hook up, one hook down
- Four-way tensioning
- Brazed center hold-down holes, with or without reinforcing washers
- Center crowns
- Rolling for rotary screens
- Brazed laps
- Skid bars
- Welded or brazed edge wires