U.S. Code of Federal Regulations

Regulations most recently checked for updates: Aug 27, 2025

§ 64.19 - External pressure.

(a) A tank without a vacuum breaker must be designed to withstand an external pressure of 7 1/2 psig or more.

(b) A tank with a vacuum breaker must be designed to withstand an external pressure of 3 psig or more.