PUBLIC UTILITIES COMMISSION OF THE STATE OF CALIFORNIA
ENERGY DIVISION RESOLUTION G-3264
August 2, 2001
Resolution G-3264. Southern California Gas Company requests the Commission's approval to use an Applied Automation Model 8000 gas chromatograph for heating value measurement and authorization to deviate from the manufacturer's recommended calibration intervals. This request was made pursuant to requirements set forth in Sections 5 and 8 of General Order 58-B, Heating Value Measurement Standard for Gaseous Fuels. Approved.
By letter dated June 23, 1999, from Southern California Gas Company.
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SUMMARY
On June 23, 1999, Southern California Gas Company (SoCalGas) requested authority to: (1) use an Applied Automation Model 8000 gas chromatograph for heating value measurement where reliable alternating current (AC) power is not readily available at remote locations; and (2) deviate from the manufacturer's recommended calibration interval from once every 60 days to once every 30 days. These requests were submitted in accordance with Sections 5 and 8 of General Order (GO) 58-B.
This Resolution approves SoCalGas's request. The Applied Automation Model 8000 gas chromatograph appears to be safe, simple, and meets the GO 58-B repeatability and accuracy requirements.
BACKGROUND
A gas chromatograph is a device operating on the principle of selective adsorption for determining the compounds that make up a gaseous mixture.
A fuel gas recording calorimeter is then used to continuously make a written record of the heating value of a fuel gas, or mixture of fuel gases, on a chart.
The latest revision of GO 58-B, Decision 84-10-052, was approved on October 17, 1984, and became effective on November 16, 1984. Sections 3q, 3r, 5a, 5b, and 8 apply to this resolution and read in part as follows:
Section 3q
A sample of natural gas of certified heating value. The sample must be of constant composition and heating value and contain no condensibles that will effect a change in its heating value with any temperature-pressure conditions to which the gas may be subjected...
Section 3r
Natural or mixed gas of constant composition and heating value, the heating value of which has been accurately determined by use of certified calibration gas. Such gas shall contain no condensibles that will effect a change in its heating value with any temperature-pressure change to which the gas may be subjected. For chromatograph type heating value measuring equipment, all components anticipated to be analyzed up to and including hexane, shall be contained in the reference calibration gas.
Section 5a
All devices measuring heating value of gaseous fuels for billing purposes must be approved by the Commission. A utility requesting Commission authorization of a device not previously approved, has the responsibility of developing and presenting appropriate data to the Commission to justify approval.
Section 5b
The request shall include a description of the new heating value measurement device, the justification for adoption, and data to demonstrate that the test results obtained from the use of such device are equal to or better than test results obtained with approved equipment. The test data obtained by the utility while testing the new device shall be compared with the data obtained from an approved type of device testing gas from the same source of supply at the same time and location. All tests must be run for a sufficient period of time to demonstrate the reliability and accuracy of the device. As a minimum, these tests shall be conducted for a period of three months. Complete records of the test shall be maintained by the utility.
Section 8
Heating value measurement devices shall be calibrated at periodic intervals using a gas of known heating value as defined in Items "q" and "r" of Section 3...Other approved heating value measurement devices shall be calibrated automatically, at intervals recommended by the manufacturer...
By letter dated June 23, 1999, SoCalGas requested authority to use an Applied Automation Model 8000 gas chromatograph for heating value measurement and to deviate from the manufacturer's recommended calibration interval. This request was submitted in accordance with Sections 5 and 8 of General Order 58-B.
The purpose of the SoCalGas request is: (1) to use the solar power feature of Model 8000 to install in locations where power from alternating current (AC) is not readily available and installation of AC power is not feasible; and (2) to reduce calibration gas maintenance costs. These reduced maintenance costs are attributed to the fact that the Model 8000 uses less helium and calibration gas, is modular in design, and is quicker and easier to repair in the field by component replacement.
Since the Applied Automation Model 8000 is a completely redesigned gas chromatograph from the Applied Automation Model EMS 12, SoCalGas needs Commission approval per Section 5 of GO 58-B to use this model of gas chromatograph in heating value measurement of gaseous fuel for billing purposes. The customer is billed on the value of energy use, which is the volume of gas used by the customer multiplied by its heating value.
SoCalGas conducted a comparison test from October 25, 1997, through January 28, 1998, using an Applied Automation Model 8000 gas chromatograph operated in parallel with an approved Daniel Model 500 gas chromatograph to measure the heating value of gas taken from the same source at the same time. The 24-hour daily averages of heating values for each gas chromatograph were recorded and compared during the test period. The averages of the heating values from the two systems did not vary more than 0.52 British Thermal Units (BTU), or 0.05% for nominal 1,018 BTU gas.
SoCalGas has been using thirty-nine Daniel Model 520 gas chromatographs, two Daniel Model 560 gas chromatographs, and twelve Chandler Model 2920 GC gas chromatographs in different locations. SoCalGas stated that the Applied Automation 8000 gas chromatograph will only be used to replace existing weekly and monthly heating value sampling tanks already located at customer sites and used for billing. However, it will not replace any existing gas chromatograph already in use.
SoCalGas is currently field testing two Model 8000 gas chromatographs but is not using them for billing. SoCalGas expects to install about 20 solar powered gas chromatographs in the next 5 years.
Sites at the BTU District typically do not have AC power readily available. Therefore, SoCalGas conducts a cost study at each site to compare the cost of bringing in AC power and the cost to install solar powered gas chromatographs.
Applied Automation Incorporated recommended an automatic calibration of Model 8000 gas chromatographs at least once every 60 days and after any maintenance. However, SoCalGas is requesting Commission approval to calibrate the units on a monthly automatic calibration interval. There is no additional cost or work for increasing the calibration interval of the Model 8000 gas chromatograph since calibrations are done automatically.
NOTICE
On June 23, 1999, SoCalGas requested authority to use the Applied Automation Model 8000 gas chromatograph for heating value measurement and permission to deviate from the manufacturer's recommended calibration interval. These requests were submitted in accordance with Sections 5 and 8 of General Order 58-B. Notice was also made by publication in the Commission Daily Calendar on August 30, 1999.
PROTESTS
No protest was filed for this request.
DISCUSSION
Energy Division has reviewed SoCalGas' request for its deviation from GO 58-B and concludes that by adopting this change, the quality of service and safety would not be impacted. There is no major safety difference between the existing and proposed models. Attachment 1 of SoCalGas's letter to the Commission dated June 23, 1999, presents the test results that demonstrate the reliability and accuracy of the Applied Automation Model 8000 gas chromatograph. The 24-hour Daily Averages (BTU) for the Applied Automation Model 8000 gas chromatograph and the Daniel Model 500 gas chromatograph were recorded and compared throughout the test. The average of the two systems did not vary from each other more than 0.52 BTU, or 0.05% for nominal 1,018 BTU gas. More frequent calibration also does not affect the performance of the proposed unit. The Applied Automation Model 8000 gas chromatograph appears to be safe, simple, and meets the GO 58-B repeatability and accuracy requirements.
Based on the data presented, Energy Division recommends that the Commission grant SoCalGas's request to: (1) use the Applied Automation Model 8000 gas chromatograph for heating value measurement where reliable AC power is not readily available at remote locations; and (2) deviate from the manufacturer's recommended calibration interval from once very 60 days to once every 30 days.
COMMENTS
This is an uncontested matter in which the resolution grants the relief requested. Accordingly, pursuant to PU Code 311(g)(2), the otherwise applicable 30-day period for public review and comment is being waived.
FINDINGS
1. By letter dated June 23, 1999, SoCalGas requested authority to use an Applied Automation Model 8000 gas chromatograph for heating value measurement, and to deviate from the manufacturer's recommended calibration interval. The request was submitted in accordance with Sections 5 and 8 of General Order 58-B.
2. SoCalGas conducted a comparison test from October 25, 1997, through January 28, 1998, using an Applied Automation Model 8000 gas chromatograph operated in parallel with an approved Daniel Model 500 gas chromatograph to measure the heating value of gas taken from the same source at the same time. The 24-hour daily averages of heating values for each gas chromatograph were recorded and compared during the test period. The averages of the heating value from the two systems did not vary more than 0.52 BTU, or 0.05% for nominal BTU gas.
3. SoCalGas expects to install about 20 gas chromatographs in the next 5 years.
4. Sites at the BTU District typically do not have AC power readily available. Therefore, SoCalGas conducts cost studies at each site to compare the cost of bringing in AC power versus the cost of installing solar powered gas chromatographs.
5. There is no additional cost or work for increasing the calibration interval of Model 8000 gas chromatograph since calibrations are done automatically.
6. The Model 8000 gas chromatograph is modular in design, and is quicker and easier to repair in the field by component replacement.
7. The Applied Automation Model 8000 gas chromatograph appears to be safe, simple, and meets the GO 58-B repeatability and accuracy requirements.
8. The Energy Division recommends that the Commission grant SoCalGas's request to: (1) use the Applied Automation Model 8000 gas chromatograph for heating value measurement, where reliable AC power is not readily available at remote locations; and (2) deviate from the manufacturer's recommended calibration interval from once every 60 days to once every 30 days.
THEREFORE IT IS ORDERED THAT:
1. The Southern California Gas Company's request, by letter dated June 23, 1999, to use the Applied Automation Model 8000 gas chromatograph for heating value measurement where reliable AC power is not readily available at remote locations, and to deviate from the manufacturer's recommended calibration interval from once every 60 days to once every 30 days, is approved.
This Resolution is effective today.
I certify that the foregoing resolution was duly introduced, passed and adopted at a conference of the Public Utilities Commission of the State of California held on August 2, 2001; the following Commissioners voting favorably thereon:
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WESLEY M. FRANKLIN
Executive Director
LORETTA M. LYNCH
President
RICHARD A. BILAS
CARL W. WOOD
GEOFFREY F. BROWN
Commissioners
Commissioner Henry M. Duque
being necessarily absent did not
participate.
