62-1791 Posted December 13, 2011 Share Posted December 13, 2011 Every now and then, my shop has to change the occasional LOX converter and every now and then we get one that only gives an output pressure of 270-280psi. IAW to my 35GS the converter is allowed to be anywhere between 270-455psi. However with this being said, there exists a conflict with the 12JG task of servicing the portable walkaround bottles. The task states that you must service to 300psi. There is also the same conflict with the aircrew's -1 stating that those bottles must indeed be at the MINIMUM of 300psi. Though I haven't actually read the -1 to confirm this, the aircrew complains enough where we end up having to change the converter once more. Why is there a 30psi gap between what my GS says is good and where the walkaround bottles are supposed to be at? Should the 35GS be changed to reflect what both the 12JG and the -1 says or is BOTH the JG and -1 wrong and I've been changing GOOD converters for no reason? The only other reference I've found about the walkaround bottles is a table in the 15x-1-1 estimating how long a bottle would last at a given setting provided the starting pressure is 300psi. Quote Link to comment Share on other sites More sharing options...
bischoffm Posted December 13, 2011 Share Posted December 13, 2011 Section 4 of the -1 says. Under a continuous breathing condition the pressure should read 295 to 315 psi. MA-1 portable oxygen system duration schedule (300 PSIG INITIAL, 50 PSIG FINAL, DISCHARGE PRESSURES) The converters have a history of coming out of rebuild with issues before. I have seen them change 4 convertors to fix the pressure and build up problem before. I'm sure you will get more info from this site. Make sure you tell them build pressure valves have also been changed and it's a two bottle system. the Job guides and GS should be changed to match the dash 1 The Quote Link to comment Share on other sites More sharing options...
Railrunner130 Posted December 13, 2011 Share Posted December 13, 2011 Could this also be an oxygen system issue, somewhere in the tubing? Quote Link to comment Share on other sites More sharing options...
62-1791 Posted December 17, 2011 Author Share Posted December 17, 2011 We figured it out, the GS is wrong AND we've been getting bad converters from supply... Those were some frustrating days... Quote Link to comment Share on other sites More sharing options...
RavenFE Posted December 20, 2011 Share Posted December 20, 2011 Not to rain on anyone's parade but the -1 section and oxygen pressure stated above are incorrect: -1, Section 1T states "in a static system under no flow, the pressure should be 270-455psi. Under a continuous breathing condition, the pressure should read 270-340psi". Quote Link to comment Share on other sites More sharing options...
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