Just installed a new Luxaire LP9C, fully modulating, 80K BTU gas furnace. Unit started fine and operated as specified for several days. Then went back to site to change some upstream gas piping. During pressure testing of the upstream gas piping the shut off valve at the furnace accidentailly got bumped and cracked open for less then a second. This exposed the gas valve to potentially as high as 15 psi pressure (but likely more down around 5 psi or so). Subseqent to this occurance no gas leaks are detectable around the units gas valve (White Rodgers 36J27-508 gas valve), and the furnace itself seems to be operating fine and is ramping up and down as usual. Anybody out there make this similar dumb mistake that might have some feedback related to the potential for damage to the gas valve itself? Manufactures recommendaiton is to not expose the valve to more than a 1/2 psi.