IMO you clean before you vip. vip lookd for rust among other things. it is counter productive to have a clean vip and then fill it with water and coat the tank with rust. General rule if the valve comes off then a vip is due.
Air testing results is ok but they are only good for the batch that was tested. a filter will say it cleans to grade E air for 40k cuft. The 40k is under certain conditions. temp humidity and other factors severly reduce that number. so if the shop does not keep up with it you done know what you get. A grade e filter is probably putting out oca for some time, perhaps half way through the life of the filter then reduces to grade e. I tend to rely on the credibility of the shop more than an air sample sheet.
Many pumpers change every few hours when they move a lot oaf gas. Face it a big shop probably is using 20 or larger compressor/S and running through a common filter system. so 8 hours of pumping is 1200 per hour and 10K a day. with a 50 cuft you are now2 pushing 3k per hour and 25k a day. Getting gas is kind of like saying which agency is best for AOW. Its the instructor not the agency that makes it a good class.
As limits go there are those that say that <40-60% is same as air and hgher treat as pure O2. there is the regs that say >23.5 requires O2 cleaning. Unless you know the background of those numbers they mean nothing. For years no O2 cleaning was done for scuba tanks less than 40%.
Air testing results is ok but they are only good for the batch that was tested. a filter will say it cleans to grade E air for 40k cuft. The 40k is under certain conditions. temp humidity and other factors severly reduce that number. so if the shop does not keep up with it you done know what you get. A grade e filter is probably putting out oca for some time, perhaps half way through the life of the filter then reduces to grade e. I tend to rely on the credibility of the shop more than an air sample sheet.
Many pumpers change every few hours when they move a lot oaf gas. Face it a big shop probably is using 20 or larger compressor/S and running through a common filter system. so 8 hours of pumping is 1200 per hour and 10K a day. with a 50 cuft you are now2 pushing 3k per hour and 25k a day. Getting gas is kind of like saying which agency is best for AOW. Its the instructor not the agency that makes it a good class.
As limits go there are those that say that <40-60% is same as air and hgher treat as pure O2. there is the regs that say >23.5 requires O2 cleaning. Unless you know the background of those numbers they mean nothing. For years no O2 cleaning was done for scuba tanks less than 40%.
