View all text of Subpart C [§ 64.57 - § 64.71]
§ 64.59 - Spring loaded pressure relief valve.
A spring loaded pressure relief valve must—
(a) Be set at a nominal pressure of 125 percent of the maximum allowable working pressure;
(b) Have a minimum normal venting capacity that is sufficient to prevent the tank pressure from exceeding 137.5 percent of the maximum allowable working pressure;
(c) Close after discharge of a pressure not lower than 115 percent of the maximum allowable working pressure; and
(d) If closed, remain closed at any pressure less than 115 percent of the maximum allowable working pressure.