Pressure vessel is a sealed container used for treating liquids or gases requiring special treatment of temperature and pressure before being forwarded for further processing. The objective of this redesign is to compare the results of software and theoretical calculation to determine the safety of pressure vessel design. The design of this fuel gas scrubber being used data from Qatar Petroleum, Bul Hanine Arabic "C" Gas Cap Recycling. The pressure vessel was designed a vertical type with the capacity of 6 m3, 40 barg for internal pressure, full vacuum for external pressure and temperature of 120 °C. These parameters were used for design process using Elite 2014 PV software and theoretical calculation using the standard of ASME Sec.VIII Div 1. Based on the comparison between software and theoretical calculations, the thickness of the shell and head of 0.9375 inch on the Elite PV and theoretical, MAWP shell of 600,839 inch, MAWP head of 610.384 inch on theoretical, then shell on PV Elite MAWP of 775.141 psi, MAWP Head of 766.561 psi and hydrostatic pressure test of 775,141 psi on theoretical calculations and PV Elite of 754.196 psi. The comparison of the methods used was shows no significant difference, but in the nozzle using the standard schedule and schedule of 160, require the addition of reinforcement plate to reach the safety factor.