Maximum injection pressure. The owner or operator shall limit injection pressure to the lessor of:
(a) A value which will not exceed the operating requirements of Sec. 144.28(f)(3) (i) or (ii) as applicable; or
(b) A value for well head pressure calculated by using the following formula: Pm=(0.800-0.433 Sg)d where: Pm=injection pressure at the wellhead in pounds per square inchSg=specific gravity of injected fluid (unitless)d=injection depth in feet. [49 FR 20197, May 11, 1984, as amended at 56 FR 41072, Aug. 19, 1991]