Proper belt installation: the back-to-basic steps

Pit & Quarry, Nov, 2004 by Paul Schmidgall

Even the most veteran plant operator may encounter the need to troubleshoot when installing a new conveyor belt. There are a number of precise procedures, each as important as the next. Cutting corners will undoubtedly result in costly, unexpected downtime. Proper belt installation always requires a back-to-basics approach, so take it one step at a time.

Step 1: Protect your investment with proper storage. First, belts should always be stored in a cool, dry building and in an area free from sunlight. Store the belt roll suspended on a tube, bar or support stand. Storing the belt flat on the ground, where moisture can penetrate exposed fabric, or storing the belt roll with weight on one edge may stretch the belt. This can cause belt camber or a bowing in the belt, resulting in serious belt mistracking.

Step 2: Lift and place the belt, aligning it with the conveyor frame. Belt rolls are usually marked with an arrow showing the direction in which they should be rolled. Typically, the load carrying side is facing up. Lift the belt roll with chain or cable attached to the ends of a center bar that passes through the core of the roll. A spreader bar above the roll prevents the chains from damaging belt edges. Place the belt on a cradle or support stand behind the conveyor, or, if space is lacking, suspend the roll above the conveyor frame for threading. Make sure the side take-up bearings are set in the retracted position to ensure maximum take-up ability after installation.

Step 3: Square the ends of the belt. Most belting is shipped from the factory with additional allowance for squaring ends for the splice. Remember that installing an unsquared belt is a common mistake, one that prevents any splice from running correctly. As molded edges on new belts are rarely straight and parallel, one must determine an accurate cut line on the belt by finding the true center point. Also, when cutting the belt, operators will often use a hand knife, but note that an inexpensive belt cutter is safer to use and will ensure a straight, accurate cut. Once squared, holes should be punched into the end of the belt (based on the fastener manufacturer's template) to prepare it for the splice.

Step 4: Thread the belt onto the conveyor. A belt is pulled onto the conveyor by threading a cable over the idlers and pulleys. Attach the cable to the belt with a clamping plate, which distributes the pulling force across the belt and prevents damage to the belt end. Place the clamping plate on the bottom side so it will pass more easily over the troughing idlers. Slowly pull the belt into position using a block and tackle or similar equipment.

Step 5: Splice the belt ends. Pull the unsquared end of the belt over the top of the squared end until the correct belt tension is obtained. Then square the remaining belt end, make the cut, and punch in the fastener holes. Placing a wooden plank under the splice point facilitates this process. Follow fastener manufacturer instructions but note that the use of belt tape under the fasteners is often recommended to help reinforce the splice area.

Step 6: Practice thorough, ongoing inspections. After installation and during initial operation, check for any abnormal conditions such as frozen idlers, excessive slippage, sideways movement or off-center loading. Also, during its wear-in period, a belt will stretch and belt retensioning is often required. Remember, thorough inspections are critical particularly during the first week of operation. After that, your daily and/or weekly scheduled maintenance will ensure efficient, economical conveyor operation.

Author Paul Schmidgall is the president and CEO of Superior Industries, a Morris, Minn.-based conveyor systems and components manufacturer. For more information, visit www.superior-ind.com.