Tips for support springs

What can be done to ensure a machine’s support springs aren’t causing it to fail prematurely? Consider the following tips:

Check your spring heights. Make sure equivalent springs (ie springs in the same location along the screen but on opposite sides) have a similar free height and then end up at similar heights (within 5mm – note some equipment manufacturers’ requirements may differ) under the static load of the machine. If the height difference is greater than 5mm (or the variation recommended by the supplier) from one side to the other, then use packers to load up the springs that are sitting higher. In configurations where the springs in a set are parallel (typical of fixed plant but also in some mobile), ensure they are at similar heights.

Keep your springs clean. Debris and fines build-up should be cleared from springs.

Never run a screen or feeder with broken or collapsed springs. Have at least two new spares on hand to remove the temptation to continue operating with broken springs while waiting for replacements. If you replace a set of springs and don’t have spares, consider buying extras at the same time.

Be consistent. Always replace equivalent springs in pairs (ie if a spring is replaced on one side of the screen, replace the spring in the same location on the opposite side).

Make sure springs can be easily inspected.

Monitor. As part of your regular checks, measure the heights of the springs while the equipment isn’t running (as they are under the weight of the machine) and record them. After each check, compare the spring heights with those previously recorded so that changes are identified. It will be obvious when a spring has catastrophically failed and, in most cases, will be evident when they are on the “way out”.

If there is suspicion about a spring, either replace it or lift the machine up and check the free heights of equivalent springs. Also compare these to their original (new) height.