14 CFR §33.64

1. (a)Strength. The applicant must establish by test, validated analysis, or a combination of both, that all static parts subject to significant gas or liquid pressure loads for a stabilized period of one minute will not:
   1. (1)Exhibit permanent distortion beyond serviceable limits or exhibit leakage that could create a hazardous condition when subjected to the greater of the following pressures:
      1. (i)1.1 times the maximum working pressure;
      2. (ii)1.33 times the normal working pressure; or
      3. (iii)35 kPa (5 p.s.i.) above the normal working pressure.
   2. (2)Exhibit fracture or burst when subjected to the greater of the following pressures:
      1. (i)1.15 times the maximum possible pressure;
      2. (ii)1.5 times the maximum working pressure; or
      3. (iii)35 kPa (5 p.s.i.) above the maximum possible pressure.
2. (b)Compliance with this section must take into account:
   1. (1)The operating temperature of the part;
   2. (2)Any other significant static loads in addition to pressure loads;
   3. (3)Minimum properties representative of both the material and the processes used in the construction of the part; and
   4. (4)Any adverse geometry conditions allowed by the type design.