N.H. Code Admin. R. Env-A 1217.04

Current through Register No. 25, June 20, 2024

Section Env-A 1217.04 - Control Techniques for External Floating Roof Tanks

An external floating roof tank meeting the applicability criteria of Env-A 1217.03 shall use the following VOC control techniques:

(a) The tank shall be fitted with:

(1) A rim-mounted secondary seal; or

(2) A closure or other device that:

a. Controls VOC emissions with an effectiveness equal to or greater than a rim-mounted secondary seal; and

b. Is approved by the EPA Administrator as a SIP or federal implementation plan revision;

(b) All seal closure equipment shall be maintained such that there are no visible holes, tears, or other openings in the seal or seal fabric;

(c) The seal shall remain intact and uniformly in place around the circumference of the floating roof between the floating roof and the tank wall;

(d) For a floating roof equipped with a vapor-mounted primary seal, the accumulated area of gaps exceeding 0.32 cm, equivalent to 0.125 in., in width between the secondary seal and the tank wall shall not exceed 21.2 sq. cm. per m., equivalent to 1.0 sq. in. per ft., of tank diameter, as determined by the method referenced in Env-A 800;

(e) All openings in the external floating roof, except for automatic bleeder vents, rim space vents, and leg sleeves, shall be equipped with covers, seals, or lids in the closed position, except when the openings are in actual use;

(f) All openings in the external floating roof, except for automatic bleeder vents, rim space vents, and leg sleeves, shall have projections into the tank that remain below the liquid surface at all times;

(g) Automatic bleeder vents shall remain closed at all times except when the roof is being floated off or being landed on the roof leg supports;

(h) Rim vents shall be set to open when the roof is being floated off the leg supports or at the manufacturer's recommended setting;

(i) Emergency roof drains shall be provided with slotted membrane fabric covers or equivalent covers which cover at least 90% of the area of the opening;

(j) Inspections in accordance with the provisions of Env-A 800 shall be performed at least semi-annually to ensure compliance with (b), (c), (e), and (f), above; and

(k) The secondary seal gap shall be measured at least annually in accordance with (d), above, and Env-A 800 when the floating roof is equipped with a vapor-mounted primary seal.

N.H. Code Admin. R. Env-A 1217.04

(See Revision Note at chapter heading for Env-A 1200) #9933, eff 6-1-11

Amended by Volume XXXIX Number 46, Filed November 14, 2019, Proposed by #12899, Effective 10/17/2019, Expires 10/17/2029