How long can a drop in liner be stored for?

A Witt PVC  drop in liner can be stored for many years before being put into service.  Because we fold the liners as tightly as we can for shipping we don’t recommend storing the liner in its shipping container for more than 30 days.  Doing so can possibly lead to a stress crack on the folds.  Even so, a stress crack can be quickly repaired with the scrap material provided in the box.

We recommend taking the liner out of the box and relaxing some of the folds.  With the liner fully unfolded on the floor loosely fold the liner in half along the shorter dimension.  Then fold the liner up across the largest dimension as needed.  Use the cardboard cores the liner is shipped with to support the liner along the folds placed in it.  The critical point is to be sure that the folds have a nice round radius and don’t come to any sharp points or creases.  This will prevent any creases from forming in the liner that could affect its fit and performance once finally installed.  Place the liner on a skid for easy movement and cover the liner with cardboard or padding.  The liner can be stored in this position for years to come.  There is a possibility that some of the plasticizer that makes the liner flexible may migrate to the surface of the liner over time.  In which case we recommend a simple leach of the liner before putting it into service.

With the liner stored in this condition a liner can be on hand for immediate installation in the case of emergency or a planned shutdown.  This is particularly advantageous for facilities with several tanks of the same dimensions.