... . grade:10,20,31.5Mpa. 4.timely delivery. this universal charging and testing unit of accessory to fill the nitrogen for accumulator ... .7CQJ-4040NXQ-*/31.5P=40D8×31.71.the charging and testing units are designed to charge,test gas pressure of nitrogen ... completely the gas in hose,finally,unload the charging tool. universal charging and testing unit,special designed