We are a relatively small full-time municipal department. Our department recently purchased ISI Viking high-pressure SCBA’s. On a few separate occasions during the first winter we encountered a potentially serious situation when the scba’s would suddenly ‘free flow’ and lose air quickly as if the by-pass was opened. We also experienced free flow conditions on days with above freezing temperature conditions. Luckily all ‘free flow sudden loss of air events’ occurred during training scenarios that did not involve live burns. ISI initially indicated that we were unique and that high moisture levels in our air supply may have caused the problem. Our Department tested the air supply and no problem was found in this regard. After much testing ISI re-engineered the pilot jet, tested different size nose cups and modified the mask retaining plate in an attempt to solve this infrequent, but potentially serious safety issue.
During the second year of operation we did not appear to experience similar failures, but we also did not perform similar outside training scenarios during sub-freezing conditions to the frequency of the previous winter. Towards the end of the second year we were informed of 2 similar events that occurred at a structure fire during sub-freezing temperature conditions, but unfortunately these incidents were not documented appropriately and insufficient information was provided. However, based on these more recent events there is still evidence that this serious safety issue has not been fully resolved. Have any other department’s experienced similar occurrences with their high-pressure ISI scba’s or other manufacturer’s high pressure scba’s? If so, please respond by email to [email protected] to share your experience, particularly if you resolved this serious safety problem. Thanks and STAY SAFE.