My health system includes nine ambulances. While I am familiar with NFPA 1917 requiring 2-hour leak tests of the cylinder O2 system and LPM measurement of the suction system, I learned that no such testing has been enforced (or carried out) in over a year. So, being assigned the ambulances this quarter, I performed a thorough check-out - documenting all measurements. Two observations I have made seem curious and I am interested in feedback from the community on what tests you perform on ambulances as well as criticism on my observations.
1. Our ambulances have four 115 VAC outlets in the rear. With the master switch and inverter switches "energized," my calibrated multimeter suggests the actual output of all but one are actually between 89.9 - 94.7 VAC.
2. Our ambulances have four Oxygen (O2) ports; two on each wall. The ports closest to the 2200 PSI O2 cylinder include a manual by-pass valve. Using a calibrated manometer and reinforced tubing tightly linking the manometer to the quick-connect adapter, O2 pressure steadily drops in each ambulance to a tune of 1 PSI/3 min on average with the engine off, master switch & O2 system switch off, O2 by-pass valve "on" or "off," and the O2 cylinder closed while connected to any O2 port in any ambulance (thus instantly failing the leak test). Using soap water, bubbles form along one or two sections of the threads on most O2 cylinder top valve assemblies. My colleagues are at odds over the significance of the bubbles - some believing it is confirmation of a leak while others claiming if it were a leak the escaping gas would be heard due to the high internal pressure and that the cylinders would need to be changed out at a quicker frequency. Based on the hours I've spent in ambulances over the past week, if these are leaks, they are not the sole cause of leak test failure. I am confident there are no leaks in TMDE set-up; a technician admitted that all the quick-connect O2 ports were swapped out in an ambulance a couple years ago due to leaks, but when checking for leaks afterwards, the new ports leaked just as much. I bought a water bottle yesterday and I intend to fill with soap water and spray onto ambulance O2 ports; if each also forms bubbles, I fear there is no reasonable way to ensure our ambulances can pass the leak test.
Thank you.