Application Manual

Maximum Allowable Working Pressure

The maximum allowable working pressure is the maximum continuous pressure for which Ariel has designed the cylinder when handling the specified fluid at the maximum temperature. Relief valves shall be provided and set to operate at no more than the Maximum Allowable Working Pressure. The MAWP is based upon the minimum of the following considerations:
  • Burst test pressure (adjusted by a safety factor which is dependent on cylinder body material)
  • Allowable bolt loading
  • Flange rating
  • Alternate cylinder bolting (17-4PH bolting).  Current cylinder MAWP are not reduced in most cases when "Sour Gas" bolting is used. The NACE MAWP are listed in the DataBook for the exceptions (17-7/8K:T:C:D:Z:U Class cylinders).
The Ariel DataBook lists only current MAWP ratings. Many cylinders have been uprated over time. Always check the cylinder nameplate for the MAWP when calculating compressor performance for existing equipment.
Maximum Allowable Working Pressure