Section 5230. Control technology guidelines

A. Petroleum liquid storage-fixed roof tanks.

1. The tank should be a pressure tank maintaining working pressure sufficient at all times to prevent vapor loss to the atmosphere, or be designed and equipped with one of the following vapor control systems:

a. An internal floating roof resting on the surface of the liquid contents and equipped with a closure seal, or seals, to close the space between the roof edge and tank shell. All tank gauging and sampling devices should be vapor tight except when gauging or sampling is taking place.

b. Any system of equal or greater control efficiency to the system in subdivision A 1 a of this section, provided such system is approved by the board.

2. There should be no visible holes, tears or other openings in the seal or any seal fabric.

3. All openings, except stub drains, should be equipped with a cover, seal or lid. The cover, seal or lid should be in a closed position at all times except when the device is in actual use. Automatic bleeder vents should be closed at all times except when the roof is floated off or landed on the roof leg supports. Rim vents, if provided, should be set to open when the roof is being floated off the roof leg supports or at the manufacturer's recommended setting.

4. The exterior above ground surfaces (exposed to sunlight) should be painted white, light pastels, or light metallic and such exterior paint should be periodically maintained in good condition. Repainting may be performed during normal maintenance periods.

B. Petroleum liquid storage-floating roof tanks.

1. The tank should be designed and equipped with one of the following vapor control systems:

a. An external floating roof resting on the surface of the liquid contents and equipped with a seal closure device (meeting the specifications set forth in subdivisions B 2 and 3 of this section) to close the space between the roof edge and tank shell. All tank gauging and sampling devices should be vapor tight except when gauging or sampling is taking place.

b. Any system of equal or greater control efficiency to the system in subdivision B 1 a of this section, provided such system is approved by the board.

2. Unless the tank is a welded tank fitted with a metallic-type shoe seal which has a secondary seal from the top to the shoe seal to the tank wall (a shoe-mounted secondary), the tank should be fitted with a continuous secondary seal extending from the floating roof to the tank wall (a rim-mounted secondary) if:

a. The tank is a welded tank, the true vapor pressure of the contained liquid is 4.0 psi or greater, and the primary seal is one of the following:

(1) A metallic-type shoe seal.

(2) A liquid-mounted foam seal.

(3) A liquid-mounted liquid-filled type seal.

(4) Any other seal closure device which can be demonstrated equivalent to the primary seals specified in subdivisions B 2 a (1) through (3) of this section.

b. The tank is a riveted tank, the true vapor pressure of the contained liquid is 1.5 psi, or greater, and the seal closure device is as described in subdivision B 2 a of this section.

c. The tank is a welded or riveted tank, the true vapor pressure of the contained liquid is 1.5 psi, or greater, and the primary seal is vapor mounted. When such primary seal closure device can be demonstrated equivalent to the primary seals described in subdivision B 2 a of this section, the provisions of that subdivision apply.

3. The seal closure devices should meet the following requirements:

a. There should be no visible holes, tears or other openings in the seal or any seal fabric.

b. The seal should be intact and uniformly in place around the circumference of the floating roof between the floating roof and the tank wall.

c. The areas where the gap between the secondary seal, installed pursuant to subdivision B 2 c of this section, and the tank wall exceeds 1/8 inch in width shall be calculated in square inches. The sum of all such areas shall not exceed 1.0 square inch per foot of tank diameter.

4. All openings, except for automatic bleeder vents, rim space vents and leg sleeves, should provide a projection below the liquid surface. All openings, except stub drains, should be equipped with a cover, seal or lid. The cover, seal or lid should be in a closed position at all times except when the device is in actual use. Automatic bleeder vents should be closed at all times except when the roof is floated off or landed on the roof leg supports. Rim vents, if provided, should be set to open when the roof is being floated off the roof leg supports or at the manufacturer's recommended setting. Any emergency roof drain should be provided with a slotted membrane fabric cover or equivalent cover that covers at least 90% of the area of the opening.

5. The exterior above ground surfaces (exposed to sunlight) should be painted white, light pastels, or light metallic and such exterior paint should be periodically maintained in good condition. Repainting may be performed during normal maintenance periods.

C. Gasoline bulk loading-bulk terminals. The control system should consist of the following:

1. A vapor collection and disposal system with the vapor disposal portion consisting of one of the following:

a. Compression-refrigeration-adsorption system;

b. Refrigeration system;

c. Oxidation system; or

d. Any system of equal or greater control efficiency to the systems in subdivisions C 1 a through c of this section, provided such system is approved by the board.

2. A vapor collection and disposal system with the vapor collection portion meeting the following criteria:

a. Loading should be accomplished in such manner that all displaced vapor and air will be vented only to the vapor disposal system. Measures should be taken to prevent liquid drainage from the loading device when it is not in use or to accomplish substantially complete drainage before the loading device is disconnected;

b. The pressure relief valves on storage containers and tank trucks should be set to release at no less than 0.7 psi or the highest possible pressure in accordance with the following National Fire Prevention Association Standards: "Standard for Tank Vehicles for Flammable and Combustible Liquids," "Flammable and Combustible Liquids Code," "Code for Motor Fuel Dispensing Facilities and Repair Garages" (see 9VAC5-20-21);

c. Pressure in the vapor collection lines should not exceed tank truck pressure relief valve settings; and

d. All loading and vapor lines should be equipped with fittings which make vapor tight connections and which close when disconnected.

D. Gasoline bulk loading-bulk plants.

1. The control system should consist of one of the following:

a. Submerged filling of account trucks and storage tanks (either top-submerged or bottom-fill) plus a vapor balance (displacement) system to control volatile organic compounds displaced by gasoline delivery to the storage tank and account truck;

b. Top loading vapor recovery method of filling account trucks and storage tanks plus a vapor balance (displacement) system to control volatile organic compounds displaced by gasoline delivery to the storage tank and account truck; or

c. Any system of equal or greater control efficiency to the system in subdivision D 1 a or b of this section, provided such system is approved by the board.

2. The control system in subdivisions D 1 a and b of this section should meet the following equipment specifications and operating procedures:

a. For top-submerged and bottom-fill. The fill pipe should extend to within six inches of the bottom of the storage tank and account truck during top-submerged filling operations. Any bottom fill is acceptable if the inlet is flush with the tank bottom; and

b. For the balance system:

(1) There should be no leaks in the account trucks' and tank trucks' pressure vacuum relief valves and hatch covers, nor tank trucks, account trucks, storage tanks or associated vapor return lines during loading or unloading operations.

(2) The pressure relief valves on storage tanks, account trucks and tank trucks should be set to release at no less than 0.7 psi or the highest possible pressure in accordance with the following National Fire Prevention Association Standards: "Standard for Tank Vehicles for Flammable and Combustible Liquids," "Flammable and Combustible Liquids Code," "Code for Motor Fuel Dispensing Facilities and Repair Garages" (see 9VAC5-20-21).

(3) Pressure in the vapor collection lines should not exceed account truck or tank truck pressure relief valve settings.

(4) All loading and vapor lines should be equipped with fittings which make vapor tight connections and which close when disconnected.

E. Transfer of gasoline-gasoline dispensing facilities-stage I vapor control systems. The control system should consist of the following:

1. A submerged fill pipe;

2. A vapor control system with the vapor recovery portion consisting of one of the following:

a. A vapor tight return line from the storage container to the tank truck which shall be connected before gasoline is transferred into the container;

b. Any adsorption system or condensation system; or

c. Any system of equal or greater control efficiency to the systems in subdivision E 2 a or b of this section, provided such system is approved by the board.

3. A vapor control system with the vapor balance portion meeting the following criteria:

a. There should be no leaks in the tank truck's pressure vacuum relief valves and hatch covers, nor truck tanks, storage tanks and associated vapor return lines during loading or unloading operations;

b. The pressure relief valves on storage containers and tank trucks should be set to release at no less than 0.7 psi or the highest possible pressure in accordance with the following National Fire Prevention Association Standards: "Standard for Tank Vehicles for Flammable and Combustible Liquids," "Flammable and Combustible Liquids Code," "Code for Motor Fuel Dispensing Facilities and Repair Garages" (see 9VAC5-20-21);

c. Pressure in the vapor collection lines should not exceed tank truck pressure relief valve settings; and

d. All loading and vapor lines should be equipped with fittings which make vapor tight connections and which close when disconnected.

F. Transfer of gasoline-gasoline dispensing facilities-Stage II vapor recovery systems.

1. Stage II vapor recovery systems shall be limited to those certified systems approved under the provisions of AQP-9, Procedures for Implementation of Regulations Covering Stage II Vapor Recovery Systems for Gasoline Dispensing Facilities (see 9VAC5-20-121), which utilize coaxial hoses and vapor check valves in the nozzle or remote vapor check valves which do not impede the performance of the functional tests required in subdivision F 6 b of 9VAC5-40-5220.

2. Stage II vapor recovery systems installed prior to January 1, 1993, must meet the specifications of a system certified by the California Air Resources Board. Owners of Stage II vapor recovery systems utilizing remote check valves which will impede the performance of the functional tests required in subdivision F 6 b of 9VAC5-40-5220 and dual vapor recovery hoses shall replace these components with check valves in the nozzle and with coaxial hoses by January 1, 1995.

Historical Notes

Derived from VR120-04-3704, eff. January 1, 1993; amended, Volume 18, Issue 07, eff. February 1, 2002.

Statutory Authority

§ 10.1-1308 of the Code of Virginia.