An important part of annual hose testing is the visual inspection of the hose - especially the liner. We unexpectedly came across some delaminated 4-inch LDH while witnessing a flow test on LDH supply hose. The goal was to see how much water could be moved through 2,000 ft of 4-inch hose using just a source pumper and an attack pumper. The result was dismal, but not related to the distance - the result was related to the delamination of the inner liner on the 4-inch LDH. Take a look at the video clip to see just how occluded some of the 4-inch LDH was. This occlusion significantly restricted flow.
Therefore, it is very important to check all fire hose liners during the annual hose test and whenever repacking hose loads. It is easy to miss delaminated liners during hose testing because water really is not flowed during the test: the test is all about static pressure. Therefore, be sure to complete a visual inspection. Any delamination issues need to be brought to the attention of the hose manufacturer.