[Code of Federal Regulations]
[Title 40, Volume 15]
[Revised as of July 1, 2005]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR65.43]

[Page 45-47]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 65_CONSOLIDATED FEDERAL AIR RULE--Table of Contents
 
                        Subpart C_Storage Vessels
 
Sec. 65.43  Fixed roof with an internal floating roof (IFR).

    (a) IFR design requirements. The owner or operator who elects to 
control storage vessel regulated material emissions by using a fixed 
roof and an internal floating roof shall comply with the design 
requirements in paragraphs (a)(1) through (4) of this section.
    (1) The internal floating roof shall be designed to float on the 
stored liquid surface except when the floating roof must be supported by 
the leg supports.
    (2) Except as provided in paragraph (a)(3) of this section, the 
internal floating roof shall be equipped with a closure device between 
the wall of the storage vessel and the floating roof edge and shall 
consist of one of the following devices:
    (i) A liquid-mounted seal.
    (ii) A metallic shoe seal.
    (iii) Two continuous seals mounted one above the other. The lower 
seal may be vapor-mounted.
    (3) If the internal floating roof is equipped with a vapor-mounted 
seal as of December 31, 1992, paragraph (a)(2) of this section does not 
apply until the next time the storage vessel is emptied and degassed, or 
by April 22, 2004, whichever occurs first.
    (4) Except as provided in paragraph (a)(4)(viii) of this section, 
each internal floating roof shall meet the following specifications:
    (i) Each opening in a noncontact internal floating roof except for 
automatic bleeder vents (vacuum breaker vents) and rim space vents is to 
provide a projection below the stored liquid surface.
    (ii) Except for leg sleeves, automatic bleeder vents, rim space 
vents, column wells, ladder wells, sample wells, and stub drains, each 
opening shall be equipped with a gasketed cover or gasketed lid.
    (iii) Each penetration of the internal floating roof shall be a 
sample well. Each sample well shall have a slit fabric cover that covers 
at least 90 percent of the opening.
    (iv) Each automatic bleeder vent and rim space vent shall be 
gasketed.
    (v) Each penetration of the internal floating roof that allows for 
passage of a ladder shall have a gasketed sliding cover.
    (vi) Each penetration of the internal floating roof that allows for 
passage of a column supporting the fixed roof shall have a flexible 
fabric sleeve seal or a gasketed sliding cover.
    (vii) Covers on each access hatch and each gauge float well shall be 
designed to be bolted or fastened when they are closed.
    (viii) If the internal floating roof does not meet any one of the 
specifications listed in paragraphs (a)(4)(i) through (vii) of this 
section as of December 31, 1992, the requirement for meeting those 
specifications does not apply until the next time the storage vessel is 
emptied and degassed, or by April 22, 2004, whichever occurs first.

[[Page 46]]

    (b) IFR operational requirements. The owner or operator using a 
fixed roof and an internal floating roof shall comply with the following 
operational requirements:
    (1) The internal floating roof shall float on the stored liquid 
surface at all times except when the floating roof must be supported by 
the leg supports.
    (2) When the floating roof is resting on the leg supports, the 
process of filling or refilling shall be continuous and shall be 
accomplished as soon as practical and the owner or operator shall 
maintain the record specified in Sec. 65.47(e).
    (3) Automatic bleeder vents are to be set to be closed at all times 
when the roof is floating except when the roof is being floated off or 
is being landed on the roof leg supports.
    (4) Each cover, access hatch, gauge float well, or lid on any 
opening in the internal floating roof shall be maintained in a closed 
position at all times (i.e., no visible gaps) except when the device is 
in actual use. Prior to filling the storage vessel, rim space vents are 
to be set to open only when the internal floating roof is not floating, 
or when the pressure beneath the rim seal exceeds the manufacturer's 
recommended setting.
    (c) IFR inspection requirements. To demonstrate compliance, the 
owner or operator shall visually inspect the internal floating roof, the 
primary seal, and the secondary seal (if one is in service) according to 
paragraphs (c)(1) through (4) of this section and maintain records of 
the IFR inspection results as specified in Sec. 65.47(c)(1).
    (1) Single seal. For vessels equipped with a single-seal system, the 
owner or operator shall perform the following inspections:
    (i) Visually inspect for IFR type A failures, the internal floating 
roof, and the seal through manholes and roof hatches on the fixed roof 
no less frequently than once every 12 months.
    (ii) Visually inspect for IFR type B failures, the internal floating 
roof, the seal, gaskets, slotted membranes, and sleeve seals (if any) 
each time the storage vessel is emptied, but no less frequently than 
once every 10 years.
    (2) Double seal. For vessels equipped with two continuous seals 
mounted one above the other, the owner or operator shall perform either 
the inspection required in paragraph (c)(2)(i) of this section or the 
inspections required in paragraph (c)(2)(ii) of this section:
    (i) Visually inspect for IFR type B failures, the internal floating 
roof, the primary seal, the secondary seal, gaskets, slotted membranes, 
and sleeve seals (if any) each time the storage vessel is emptied, but 
no less frequently than once every 5 years; or
    (ii) Visually inspect the internal floating roof and the other 
components as specified in the following:
    (A) For IFR type A failures, inspect the secondary seal through 
manholes and roof hatches on the fixed roof no less frequently than once 
every 12 months; and
    (B) For IFR type B failures, inspect the primary seal, the secondary 
seal, gaskets, slotted membranes, and sleeve seals (if any) each time 
the vessel is emptied, but no less frequently than once every 10 years.
    (3) For inspections to determine if any IFR type B failures are 
present as required by paragraphs (c)(1)(ii), (c)(2)(i), and 
(c)(2)(ii)(B) of this section, the owner or operator shall comply with 
the refilling notification requirements specified in Sec. 65.48(c)(1).
    (4) After installing the control equipment required to comply with 
Sec. 65.42(b)(1) or (3), visually inspect the internal floating roof, 
the primary seal, and the secondary seal (if one is in service) prior to 
filling the storage vessel with regulated material. If there are holes, 
tears, or other openings in the primary seal, the secondary seal, or the 
seal fabric, or defects in the internal floating roof, the owner or 
operator shall repair the items before filling the storage vessel.
    (d) IFR repair requirements. The owner or operator shall repair any 
observed or determined failures according to paragraphs (d)(1) and (2) 
of this section:
    (1) If an IFR type A failure is observed, the owner or operator 
shall repair the items or empty and remove the storage vessel from 
service within 45 calendar days. If the failure cannot be repaired 
within 45 calendar days or if the vessel cannot be emptied within 45 
calendar days, the owner or operator may utilize up to two extensions of 
up

[[Page 47]]

to 30 additional calendar days each and keep the records specified in 
Sec. 65.47(d).
    (2) If an IFR type B failure is determined, the owner or operator 
shall repair the items and comply with the refilling notification 
requirements of Sec. 65.48(c)(1) before refilling the storage vessel 
with regulated material.