Chapter PSC 134

PSC 134.21(4) (4) For required periodic heating value tests see s. PSC 134.25. The specific gravity of the gas shall be determined at least once each month when there is no change in the type or sources of gas and when there is a change in the type of gas. Whenever emergency or peak shaving plants are ran or when mixed gases are used, daily determinations of specific gravity shall be made.

PSC 134.21 History History: Cr. Register, February, 1959. No. 38, eff. 3-1-59.

PSC 134.22 PSC 134.22 Purity of gas.

PSC 134.22(1) (1) In no case shall gas contain more than 30 grains of sulphur per 100 standard cubic feet, 5 grains of ammonia per 100 standard cubic feet, nor more than 0.1 grain of hydrogen sulphide per 100 standard cubic feet. (Exception. If the gas is not to be placed in pipe or bottle type holders the hydrogen sulphide content may be 0.3 grains per 100 standard cubic feet.)

PSC 134.22(2) (2) Utilities supplying gas containing coal or water gas shall make quantitative determinations of total sulphur at least once every 6 months and qualitative hydrogen sulphide tests at intervals of 1 hour to 2 weeks depending upon the probability of this impurity being found.

PSC 134.22(3) (3) Utilities supplying liquefied petroleum gas, or liquefied petroleum air mixtures, or natural gas shall test the gas periodically for impurities or periodically obtain data concerning impurities from sources they believe the commission can accept as reliable.

PSC 134.22 History History: Cr. Register, February, 1959, No. 38, eff. 3-1-59.

PSC 134.23 PSC 134.23 Pressure variation.

PSC 134.23(1) (1) Every utility supplying gas shall file with the commission a standard service pressure by service areas. The service pressure shall be of such a value that the maximum pressure at any outlet as specified below shall not be greater than 12 inches of water column except for customers utilizing high-pressure service.

PSC 134.23(2) (2) For customers receiving standard service pressure, the gas pressure at the outlet of the utility’s service meters shall meet the following requirements:

PSC 134.23(2)(a) (a) At no outlet in the service area shall it ever be greater than one and one-fourth of the standard service pressure nor greater than 12 inches of water nor ever be less than one-half of the standard service pressure nor less than 4 inches of water.

PSC 134.23(2)(b) (b) At any single outlet it shall never be greater than twice the actual minimum at the same outlet.

PSC 134.23(2)(c) (c) At any one outlet the normal variation of pressure shall not be greater than the following:

- See PDF for table

PSC 134.23(3) (3) For customers utilizing gas at high pressure, a service pressure shall be agreed upon by the utility and the customer, and the maximum pressure variation shall not exceed 15% of the agreed pressure unless the commission shall authorize a greater variation.

PSC 134.23(4) (4) No utility shall furnish gas to any customer at pressures higher than its filed standard service pressure until it has filed with the commission acceptable service rules governing high-pressure service to customers desiring to utilize gas at pressures higher than standard service pressure. Such service rules shall provide that the utility will make high-pressure service available to its customers upon request whenever high pressure gas is available at the customer’s premises or may be made available in accordance with the utility’s filed extension rules, and when such high pressure is required for proper operation of the customer’s present or proposed utilization equipment.

PSC 134.23 History History: Cr. Register, February, 1959, No. 38, eff. 3-1-59.

PSC 134.25 PSC 134.25 General use of calorimeter equipment.

PSC 134.25(1) (1) Unless specifically directed otherwise a calorimeter shall be maintained at each gas producing or mixing plant whether the plant is in continuous operation or used only for standby or peak shaving purposes. The calorimeter shall be used to check the operation of the plant and shall measure the heating value of the gas going to the gas lines.

PSC 134.25(2) (2) Unless specifically directed otherwise calorimeters shall be maintained in operation in locations where the heating value of the gas can be measured from each different supplier.

PSC 134.25(3) (3) Unless specifically directed otherwise a calorimeter shall be maintained and used to measure the heating value of the gas actually sold to customers in those cases where mixed gases are used.

PSC 134.25(4) (4) Tests of heating value of the gas shall be made daily whenever gas is supplied at the calorimeter location unless specifically directed otherwise by the commission. The original records of the tests shall be dated, labeled and kept on file for 6 years. A copy of the daily average heating value of gas sold to customers shall be sent to the commission each calendar month.

PSC 134.25(5) (5) The calorimeter equipment shall be maintained so as to give results within + or - 1%. Recording calorimeters used to test or control the production or mixing of gas or measure the heating value of purchased gas when therm rates are not applicable shall be tested with a gas of known heating value at least 3 times a year or when the accuracy is in question. Recording calorimeters used only with standby or peak shaving production plants shall be tested with a gas of known heating value at least 2 times a year. Non-recording calorimeter equipment such as the Junkers shall be tested with a gas of known heating value at least once a year or tested against another calorimeter of known accuracy at least once a year.

PSC 134.25 History History: Cr. Register, February, 1959, No. 38, eff. 3-1-59; am. (5), Register, January, 1965, No. 109, eff. 2-1-65.

PSC 134.251 PSC 134.251 Use of recording calorimeter for therm billing.

PSC 134.251(1) (1) In the application of gas rates based on the therm, a recording calorimeter shall be used to determine the heating value of the gas being distributed to utility customers. These calorimeters will be located as set forth in s. PSC 134.25 (2) and (3). They shall have such accuracy characteristics as to be able to measure the heating value of the gas to within + or -2 B.t.u., shall be able to reproduce these readings to within +or - 2 B.t.u., and shall be able to hold their accuracy over an extended period of time. The instruments shall be installed in accordance with the manufacturer’s recommendations.

PSC 134.251(2) (2) Each utility selling gas shall file with the commission a complete installation report stating the following information: location of calorimeter, kind of gas tested, type of scale, uniform or split scale range, date installed, publication number of manufacturer’s applicable book of instructions, outline of the building, the location of the calorimeter or calorimeters within the building, the size, length, gas pressure, and general route of the gas sample pipe from the supply main to each calorimeter and location of all secondary equipment necessary for the operation of the recording calorimeter.

PSC 134.251(3) (3) 

PSC 134.251(3)(a) (a) Each utility selling gas shall keep a chronological record of dates and results of tests and operations performed on the calorimeter to test and maintain accuracy.

PSC 134.251(3)(b) (b) Twice every month the following tests shall be made:

PSC 134.251(3)(b)1. 1. Two days of each month shall be selected for the performance of an “as found” accuracy test, mechanical tests, adjustments, and an “as left” accuracy test of each recording calorimeter, and thereafter the specified accuracy tests, adjustments, and maintenance work shall be performed on the same days of each month insofar as practicable.

PSC 134.251(3)(b)2. 2. In making the accuracy tests on the calorimeter, the utility shall use reference natural gas which has been certified by the Institute of Gas Technology before cleaning parts or making any adjustments to either the tank unit or the recorder mechanism. The change from line gas to the certified gas should be made so as to have a continuous chart recording. The inlet pressure used should be the same for both calibration and subsequent operation.

PSC 134.251(3)(b)3. 3. If the “as found” accuracy test is within + or -3 B.t.u., no adjustment will be required and the instrument may be returned to service. If the “as found” accuracy test is not within + or - 3 B.t.u., maintenance shall be performed to restore the accuracy of the instrument.

PSC 134.251(3)(b)4. 4. In order that adequate information concerning each cylinder of natural gas which is to be used for the semi-monthly check tests be available at all times, the following information shall be entered on a form or in a log book provided for the purpose and also on a label or tag securely attached to each cylinder in which the gas is stored:

PSC 134.251(3)(b)4.a. a. Institute of Gas Technology Cylinder Number.

PSC 134.251(3)(b)4.b. b. Institute of Gas Technology Certificate Number.

PSC 134.251(3)(b)4.c. c. Date cylinder was certified.

PSC 134.251(3)(b)4.d. d. Date cylinder was received by the utility.

PSC 134.251(3)(b)4.e. e. Heating value certified by Institute of Gas Technology.

PSC 134.251(3)(b)4.f. f. Basis of the heating value in subd. 4. e.

PSC 134.251(3)(b)4.g. g. Heating value to be used in the semi-monthly accuracy tests. This heating value will not include any plus or minus values. For example, if the heating value is 1,000 + or - 0.9 B.t.u. per cubic foot, the heating value is 1,000 B.t.u. per cubic foot.

PSC 134.251(3)(b)4.h. h. Basis of the heating value in subd. 4. g.

PSC 134.251(5) (5) The original chart records produced by the recording calorimeters shall be dated, labeled, and kept on file for 6 years. A copy of the daily average heating value of gas and the results of the semi-monthly“as found” and “as left” test shall be sent to the commission each calendar month.

PSC 134.251(6) (6) A gravitometer may be substituted for the calorimeter equipment required to control standby or peak shaving plants in subs. (1) and (5) provided the heat content of the standby or peak shaving gas produced does not directly affect the therm billing of the gas customer receiving it.

PSC 134.251 History History: Cr. Register, January, 1965, No. 109, eff. 2-1-65; cr. (6), Register, July, 1983, No. 331, eff. 8-1-83.

PSC 134.26 PSC 134.26 Meter testing and testing equipment.

PSC 134.26(1) (1) Each public utility giving gas service is responsible for the accuracy of equipment used to measure service to its customers and all gas supplied by the utility shall be metered unless specific exemption is obtained from the public service commission. The utility shall own and maintain the equipment and facilities necessary for accurately testing the various types and sizes of meters used by the utility for the measurement of gas, shall make the tests required by these rules, shall maintain the measuring devices, and maintain their accuracy; unless arrangements are made to have the work done by others who have properly equipped laboratories, are approved by the commission and arrangements are also made to have equipment and procedures checked by the public service commission. A test by the manufacturer of a metering device is not acceptable unless witnessed by a utility representative.

PSC 134.26(2) (2) Each public utility giving gas service shall own and maintain, except as provided in sub. (1), a meter prover of sufficient capacity to test meters in accordance with s. PSC 134.28. The meter prover shall be complete with all accessories needed for accurate meter testing, shall be suitably located for meter testing, and shall be protected from drafts and excessive temperature changes. The equipment shall be maintained in good condition and correct adjustment and be capable of determining the accuracy of service meters to within one-half of one per cent. When the meter prover is used to test temperature-compensating meters, there shall be present a temperature-indicating device to accurately determine the temperature of the prover to within + or - 1° Fahrenheit.

PSC 134.26(3) (3) Each public utility giving gas service through turbine or rotary displacement type meters shall a) own and maintain, except as provided in sub. (1), a flow or volumetric meter of suitable capacity, together with necessary accessories, and it shall maintain such equipment in proper adjustment so that it will be capable of determining the accuracy of turbine or rotary displacement type meters to within one-half of one percent; or b) have a record of tests of each turbine or rotary displacement type meter made by an acceptable laboratory or by a manufacturer witnessed by a representative of the utility. The record should show that the test included a check of the recording device.

PSC 134.26(4) (4) Each public utility giving gas service through orifice type meters shall own and maintain, except as provided in sub. (1), instruments for checking the diameter of the orifice, a water column for testing the pressure differential recorder, and a mercury column or a dead weight gauge tester for testing the static pressure recorder so that the utility will be capable of determining the accuracy of these orifices and recorders to within one-half of one per cent.

PSC 134.26(5) (5) All instruments and equipment used for testing of meters shall be maintained in good condition and correct adjustment and be capable of determining the accuracy of service meters to within one-half of one percent. Bell type provers shall be checked at least once each 3 years against a standard by either the bottling or strapping method. All electrical and electronic equipment associated with testing equipment shall be tested every 6 months.

PSC 134.26(6) (6) A rotary displacement type meter, when used as a standard for testing other service meters, shall be given a differential test every 6 months. An original differential test record of the standard meter shall be established and all future differential test results shall be recorded and compared with the original test record. When the test differential pressure differs from the original test record by more than 25% at approximately 25% of the capacity of the meter, the meter shall be cleaned and/or repaired. All associated electrical equipment shall be tested before each series of tests. Associated pressure and temperature correction equipment shall be tested every 6 months.

PSC 134.26(7) (7) A diaphragm-type meter shall not be used as a standard for testing other service meters.

PSC 134.26(8) (8) The temperature in the proving and meter storage rooms shall not vary by more than ±3° Fahrenheit, or testing shall be stopped. If the proving equipment can compensate for a temperature differential between the proving equipment and the meter, then testing may be performed within the proving equipment temperature specification. The proving and meter storage rooms shall be equipped with a temperature recording device. A meter shall be stored in the temperature controlled area a minimum of 12 hours before being tested. The meter shop shall be kept in a clean and orderly manner.

PSC 134.26 History History: Cr. Register, February, 1959. No. 38, eff. 3-1-59; am. (2), Register, January, 1965, No. 109, eff. 2-1-65.; am. (3) and (5), cr. (6) and (7), Register, April, 1969, No. 160, eff. 5-1-69; am. (2) and (5), cr. (8), Register, November, 1989, No. 407, eff. 12-1-89.

PSC 134.27 PSC 134.27 Meter accuracies. All meters shall be set as close to 100% accurate as possible. Diaphragm meters shall be considered correct for service if the results of the multiple tests called for agree within 1% and no test shows an error of more than 1% fast or slow. Turbine and rotary displacement type meters shall be considered correct for service when tested at approximately 10% of rated flow with accuracy between 2% slow and 2% fast, and at approximately 100% flow with accuracy between 1% slow and 1% fast and in the case of turbine type meters, have a spin test time equal to or greater than that on file with the commission under s. PSC 134.28 (6). In orifice type meters, the deviations in the diameter of the orifice shall not exceed the following:

- See PDF for table

In orifice type meters the sharpness of the orifice edge shall be maintained in such a condition that the upstream edge of the orifice shall not appreciably reflect a beam of light when viewed without magnification. No meter which is mechanically defective shall be placed in service or allowed to remain in service after such defect has been discovered. The inlet and outlet of diaphragm type meters shall be capped when not connected in service.

PSC 134.27 History History: Cr. Register, February, 1959. No. 38, eff. 3-1-59; am. (intro.), Register, November, 1962, No. 83, eff. 12-1-62; am.(intro.), Register, April, 1969. No. 160, eff. 5-1-69.

PSC 134.28 PSC 134.28 Meter testing.

PSC 134.28(1) (1) Each meter test of a diaphragm type meter with a capacity of 2,400 cubic feet per hour or less shall consist of one proving at a rate of flow of 15 to 30% of the rated capacity of that meter and one proving at a rate of flow at 90 to 120% of the rated capacity of the meter. The capacity of the meter for test purposes shall be the capacity at one-half inch water column differential pressure.

PSC 134.28(2) (2) Each meter test of a diaphragm type meter having a capacity greater than 2,400 cubic feet per hour shall consist of one proving at a rate of flow of 15 to 30% of the rated capacity of that meter and one proving at a rate of flow of 90 to 120% of the rated capacity of the meter but not less than 2,500 cubic feet per hour. The capacity of the meter for test purposes shall be the capacity at one-half inch water column differential pressure.

PSC 134.28(3) (3) Rotary meters shall be tested at 2 loads with the minimum load at 10% of rating by the use of a portable or volumetric meter or other approved proving devices, or be given a differential test. In the latter case an original test record shall be set up immediately after installation; future differential test results shall be recorded and compared with the original test record.

PSC 134.28(4) (4) A test of an orifice meter shall consist of tests of the recording gauges, and the removal, inspection and measurement of the orifice.

PSC 134.28(5) (5) Temperature-compensated gas displacement meters when tested shall be proved to a base temperature of 60° Fahrenheit.

PSC 134.28(6) (6) Turbine-type meters shall be tested at 2 loads with the minimum load at 10% of rating by the use of a portable or volumetric meter or other approved proving devices, or be given a turbine blade, rotor and gear assembly spin test, either by manual or velocity rotation. Before a particular type turbine meter can be used, the manufacturer must file with and be accepted by the commission a minimum coasting time which will satisfactorily indicate the operating condition of the internal metering mechanism. For the spin test method a test record shall be set up; and the original and subsequent spin test results shall be recorded and compared with the specified minimum coasting time as filed with the commission for that type meter.

PSC 134.28 History History: Cr. Register, February, 1959, No. 38, eff. 3-1-59; am. (3), Register, November, 1962, No. 83, eff. 12-1-62; cr. (5), Register, January, 1965, No. 109, eff. 2-1-65; cr. (6), Register, April, 1969, No 160, eff. 5-1-69; am. (1) and (2), Register, November, 1989, No. 407, eff. 12-1-89.

PSC 134.29 PSC 134.29 Installation test. No meter shall be used to meter gas consumption for billing purposes unless it was tested and found correct, as defined in s. PSC 134.27 not longer than 15 months previous to its use. The first test on a meter or a retest after a major overhaul shall include a check of the registering device and linkages.

PSC 134.29 History History: Cr. Register, February, 1959, No. 38, eff. 3-1-59; am. Register, April, 1969, No. 160, eff. 5-1-69.

PSC 134.291 PSC 134.291 Statistical sample testing plan for new meters. The following new meter sample testing plan may be used for testing new meters instead of the new meter test requirements of s. PSC 134.26 (1), if the commission authorizes the adoption of the plan by a utility.

PSC 134.291(1) (1) Meters, as received from the manufacturer, shall be divided into homogeneous lots by manufacturers and types. The maximum number of meters in any lot may not exceed 1,000 or be less than 96. From each such lot assembled, there shall be drawn a coded sample size specified in Military Standard 414 (MIL-STD-414) dated 11 June 1957, as shown for the various group sizes using Inspection Level IV of Table A-2 on page 4 and a corresponding actual sample size as shown on Table B-3 on page 45. The sample shall be drawn by a random method that ensures that each meter in the lot has an equal chance of being selected.

PSC 134.291(2) (2) The test criterion for acceptance or rejection of each lot shall be based on a separate analysis conducted at both the open and check flow rate, as specified in s. PSC 134.28 (1) by means of the Standard Deviation Method, Double Specification Limit and with an Acceptable Quality Level (AQL) of .25 for the open accuracy analysis and an AQL of .40 for the check accuracy analysis as shown in Table B-3, MIL-STD-414, page 45. The statistical analysis calculations shall be made following the example on page 43 of MIL-STD-414 with the upper and lower specification limits U and L designated at 101% and 99% respectively.

PSC 134.291(3) (3) One nonregistering meter may be removed from the sample lot for analysis purposes and replaced with another randomly selected meter. If more than one meter in a sample is found not to be registering, the entire lot shall be rejected.

PSC 134.291(4) (4) A lot shall be deemed acceptable for installation if the total estimated percent defective (P) is less than the appropriate maximum allowable percent defective (M) as determined from Table B-3 under the procedures of sub. (2). All meters in an acceptable lot shall be deemed to have met the accuracy requirements of s. PSC 134.26 (1) for placement in service without further testing.

PSC 134.291(5) (5) A lot shall be considered rejected and not acceptable for installation if the total estimated percent defective (P) exceeds the appropriate maximum allowable percent defective (M) as determined from Table B-3 under the procedures of sub. (2). All meters in a rejected lot shall be tested and adjusted in accordance with the procedures of s. PSC 134.27 or replaced with meters meeting these requirements.

PSC 134.291 Note Note: Military Standard 414 is on file at offices of the Public Service Commission, Secretary of State and Legislative Reference Bureau offices.

PSC 134.291 History History: Cr. Register, November, 1989, No. 407, eff. 12-1-89.

PSC 134.30 PSC 134.30 Periodic testing and maintenance. Each utility shall test its meters according to the following schedule except as provided in s. PSC 134.26 (1). Where pressure regulators, volume corrective devices, or other measuring devices are used on the service or used in conjunction with the meters, they shall be tested on the same schedule as the meters.

PSC 134.30(1) (1) All diaphragm meters that are measuring dry gas and have non-absorptive type diaphragms or were rediaphragmed since the introduction of dry gas shall be due for removal from service, tested, adjusted, repaired if necessary, and retested if reused, every 180 months if the meter capacity is 2,400 cubic feet per hour or less at 1⁄2-inch water column and every 48 months if the capacity is greater than 2,400 cubic feet. Meters shall be tested during the calendar year in which said 180th or 48th month falls.

PSC 134.30(2) (2) All diaphragm meters that are measuring dry gas that do not have non-absorptive-type diaphragms and have not been rediaphragmed since the introduction of dry gas shall be removed from service, tested, adjusted, re-diaphragmed and retested within 48 months of the introduction of dry gas if the meter capacity is 2,400 cubic feet per hour at 1⁄2-inch water column and within 24 months if the capacity is greater than 2,400 cubic feet.

PSC 134.30(3) (3) All diaphragm meters that measure other than dry gas shall be removed from service, tested, adjusted, repaired, if necessary, and retested if reused every 96 months if the meter capacity is 2,400 cubic feet per hour or less at 1⁄2-inch water column and every 48 months if the capacity is greater than 2,400 cubic feet.

PSC 134.30(4) (4) Rotary meters having a capacity of 15,000 cubic feet per hour or less at 4 oz. water column pressure shall be given a differential test at least once every 96 months and once every 48 months if the capacity is greater than 15,000 cubic feet. When the differential differs from the original test record by more than 50%, the meter shall be cleaned and/or repaired.

PSC 134.30(5) (5) Orifice meters shall have their differential and static recording gauges tested at least once each month, the diameter and condition of the orifice checked at least once a year. The specific gravity of the gas shall be checked as required in s. PSC 134.21 (4), and any temperature recording devices tested annually.

PSC 134.30(6) (6) Turbine meters shall be given an inspection and spin test at least once every 12 months. When the coasting time is equal to or less than the specified minimum coasting time as on file with the commission, the meter shall be cleaned and/or repaired.

PSC 134.30(7) (7) Turbine meters which are capable of automatically adjusting shall be inspected and tested at least once every 12 months. They shall be tested in accordance with s. PSC 134.28 (6) or with the use of the meter manufacturer’s electronic field prover.

PSC 134.30(8) (8) Whenever an automatically adjusting turbine meter automatically adjusts the volume for plus or minus 5% or more while in operation at a steady flow rate of 10% or more of the meter’s rated capacity, the meter shall be cleaned and/or repaired.

PSC 134.30(9) (9) Whenever an automatically adjusting turbine meter is being tested at a steady flow rate of 10% or more of the meter’s rated capacity and indicates an error of plus or minus 1% or more, the meter shall be cleaned and/or repaired.

PSC 134.30 History History: Cr. Register, February, 1959, No. 38, eff. 3-1-59; am. (4), Register, November, 1962, No. 83, eff. 12-1-62; am. (1), Register, January, 1965, No. 109, eff. 2-1-65; am. (4) and cr. (6), Register, April, 1969, No. 160, eff. 5-1-69; cr. (7) to (9), Register, December, 1984, No. 348, eff. 1-1-85; am. (1) and (4), Register, November, 1989, No. 407, eff. 12-1-89.

PSC 134.31 PSC 134.31 Request and referee tests.