Section 215.241  External Floating Roofs

The requirements of subsection 215.124(a) shall not apply to any stationary storage tank equipped with an external floating roof:  

a)         Exempted under Section 215.123(a)(2) through (a)(6);

b)         Of welded construction equipped with a metallic-type shoe seal having a secondary seal from the top of the shoe seal to the tank wall (shoe-mounted secondary seal);

c)         Of welded construction equipped with a metallic type shoe seal, a liquid-mounted foam seal, a liquid-mounted liquid-filled-type seal, or other closure device of equivalent control efficiency approved by the Agency in which a petroleum liquid with a true vapor pressure less than 27.6 kPa (4.0 psia) at 294.3º K (70º F) is stored; or

d)         Used to store crude oil with a pour point of 50º F or higher as determined by ASTM Standard D97-66 incorporated by reference in Section 215.105.

(Source:  Amended at 14 Ill. Reg. 9173, effective May 23, 1990)