N.J. Admin. Code § 7:27B-3.16

Current through Register Vol. 56, No. 21, November 4, 2024

Section 7:27B-3.16 - Procedures for determining the efficiency of gasoline vapor recovery systems at service stations

(a) The method for this section is applicable for the determination of the efficiency of vapor recovery systems controlling gasoline vapors emitted during the filling of underground storage tanks. For the same circumstances as described above, any alternative method shall be submitted to the Department for review pursuant to 7:27B-3.2(c), (d) and (e).

(b) This method is based upon the amount of gasoline vapor discharged from the atmospheric vent(s) of underground storage tank(s) being filled. The procedure is intended for all control systems which have a vapor recovery line connecting the underground storage tank to the tank truck.

(c) The following is a summary of this method:

1. A positive displacement meter is mounted on each atmospheric vent pipe to determine the amount of vapor displaced during the filling of underground storage tanks. The efficiency of the vapor recovery system is determined by comparing the amount of vapor emitted from the atmospheric vents with the total amount of gasoline transferred to the underground storage tanks.

2. For the purpose of this procedure, a single test shall be sufficient to establish the efficiency of the vapor recovery system.

(d) The following is a list of equipment used in this method:

1. Gas meter device: a positive displacement meter with a capacity of 3000 SCFH and a pressure drop of 0.05 inches of water at an air flow of 30 SCFH. This meter shall be designed to read (in 0.1 cubic foot increments) only the amount of positive vapors displaced and shall allow for any negative in-breathing. The meter shall be equipped with taps for a thermocouple and a pressure sensor;

2. Coupling for atmospheric vent pipe: a coupling to connect the gas metering device to the atmospheric vent pipe. Coupling shall be sized for a minimum pressure drop;

3. Thermocouples: temperature sensing devices to measure the temperature of the vapors emitted at the gas metering device and ambient temperature; and

4. Manometer: liquid manometer or other equivalent pressure sensing device capable of measuring zero to ten inches of water at the gas metering device.

5. Leak detection equipment standards shall be as follows:

i. The leak detection equipment shall be certified as safe for operation in explosive atmospheres;

ii. The monitoring instrument detector shall be capable of measuring the leak definition concentration specified in the appropriate section in N.J.A.C. 7:27-16. Detector types meeting this requirement include but are not limited to catalytic oxidation, flame oxidation, infrared absorption and photoionization; and

iii. The instrument shall be readable to within five percent of the specific leak concentration and shall have a response time of 30 seconds or less.

(e) The procedure for this section shall be as follows:

1. Mount the positive displacement meter to the top of the atmospheric vent of the storage tank(s). If the vent has restriction, remove the restriction before mounting the meter;

2. Connect the manometer and thermocouple to the taps on the meter;

3. Connect tank truck fuel and vapor return hoses to the underground storage tanks in accordance with procedures outlined by the manufacturer;

4. Check the tank truck and all vapor return line connections with a leak detection instrument for a tight seal before and during the test;

5. Record the initial reading of the gas meter(s);

6. Start the transfer of gasoline to the storage tank(s) in accordance with facilities' established normal procedures;

7. Record temperature, pressure, and gas meter readings at two minute intervals;

8. Record at the start and the end of the test the barometric pressure and ambient temperature;

9. Disconnect the tank truck hoses from the storage tank in accordance with the procedures outlined by the facility when the transfer has been completed;

10. Continue to record temperature, pressure, and gas meter readings at the underground storage tank vent(s) at two-minute intervals for a period of ten minutes after the completion of the gasoline transfer;

11. Record the final reading of the gas meter;

12. Record the total volume of gasoline that was transferred; and

13. Disconnect the positive displacement meter from the atmospheric vent.

(f) Calculate the efficiency of the vapor recovery system using the following equation:

E=1 -	V[v] (7.481) (T[s] + 460) (P[b])	x 100
...........................
V[T] (T[v] + 460 (29.92)

Where:

E=Percent efficiency of the vapor recovery system at standard conditions.

V[v]=Volume of displaced vapors vented from the atmospheric vent in actual cubic feet (ACF).

V[T]=Volume of gasoline transferred to storage tanks in gallons.

T[v]=Temperature of vapors vented from atmospheric vent in degrees Fahrenheit.

T[s]=Standard temperature (70 [degree]F).

P[b]=Average barometric pressure during test in inches of mercury.

7.481=Conversion factor of gallons per cubic foot (Gal/ft[LESS THAN]3[GREATER THAN]).

29.92=Standard pressure in inches of mercury.

(g) The test report shall include the following information submitted on the required reporting forms listed in Appendix H. (Any alternative report form shall be submitted to the Department for review pursuant to 7:27B-3.2(c) and (e)) :

1. A dimensioned sketch of the sampling location detailing number of storage tanks, type of fill pipe; and type of vapor recovery system;

2. The total amount of each type of gasoline transferred;

3. The size of the storage tank(s) into which the gasoline was transferred;

4. The total amount of gasoline present in the storage tank(s) prior to transfer;

5. Pressure/vacuum test date listed on the tank truck; and

6. Identification of the tank truck.

N.J. Admin. Code § 7:27B-3.16