Proper purging procedure for ALL New LP gas Tanks (5# to 90,000 gallon)
On a new cylinder/tank or a cylinder/tank that has been opened to atmosphere for repair you need to introduce LP gas VAPOR at 15 psi, once the tank equalizes you need to vent or purge this to atmosphere, this procedure needs to be done 5 times. Then the tank can be filled with Liquid. It is also recommended that methanol be added on initial fill to combat moisture. Improperly purged tanks will cause freeze ups, pilot/flame outages and premature relief valve operation. A vacuum purged tank can forgo this procedure and be filled the "first" time. Also you cannot count on an opd for filling they are a safety measure mandated by the CPSC and they sometimes fail. The only proper procedure is to fill by weight (tare + cylinder volume)