14 CFR § 33.64

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:

Exhibit permanent distortion beyond serviceable limits or exhibit leakage that could create a hazardous condition when subjected to the greater of the following pressures:

1.1 times the maximum working pressure;

1.33 times the normal working pressure; or

35 kPa (5 p.s.i.) above the normal working pressure.

Exhibit fracture or burst when subjected to the greater of the following pressures:

1.15 times the maximum possible pressure;

1.5 times the maximum working pressure; or

35 kPa (5 p.s.i.) above the maximum possible pressure.

Compliance with this section must take into account:

The operating temperature of the part;

Any other significant static loads in addition to pressure loads;

Minimum properties representative of both the material and the processes used in the construction of the part; and

Any adverse geometry conditions allowed by the type design.