Virginia Administrative Code
Title 9 - ENVIRONMENT
Agency 5 - STATE AIR POLLUTION CONTROL BOARD
Chapter 40 - EXISTING STATIONARY SOURCES
Part II - Emission Standards
Article 25 - Emission Standards for Volatile Organic Compound Storage and TransferOperations (Rule 4-25)
Section 9VAC5-40-3420 - Definitions

A. For the purpose of these regulations and subsequent amendments or any orders issued by the board, the words or terms shall have the meanings given them in subsection C of this section.

B. As used in this article, all terms not defined here shall have the meanings given them in 9VAC5 Chapter 10 (9VAC5-10-10 et seq.), unless otherwise required by context.

C. Terms defined.

"External floating roof" means a storage vessel cover in an open top tank consisting of a double deck or pontoon single deck which rests upon and is supported by the liquid being contained and is equipped with a closure seal or seals to close the space between the roof edge and tank shell.

"Internal floating roof" means a cover or roof in a fixed roof tank which rests upon or is floated upon the liquid being contained and is equipped with a closure seal or seals to close the space between the roof edge and tank shell.

"Liquid-mounted" means a primary seal mounted so the bottom of the seal covers the liquid surface between the tank shell and the floating roof.

"Submerged fill pipe" means any fill pipe the discharge opening of which is entirely submerged when the liquid level is six inches above the bottom of the tank; or, when applied to a tank which is loaded from the side, any fill pipe the discharge opening of which is entirely submerged when at the minimum operating level.

"Vapor-mounted" means a primary seal mounted so there is an annular vapor space underneath the seal. The annular vapor space is bounded by the bottom of the primary seal, the tank shell, the liquid surface, and the floating roof.

"Vapor tight" means capable of holding a pressure of 18 inH20 and a vacuum of 6 inH20 without sustaining a pressure change of more than 3 inH20 in five minutes.