DEPARTMENT OF LICENSING AND REGULATORY AFFAIRS  
PUBLIC SERVICE COMMISSION  
TECHNICAL STANDARDS FOR GAS SERVICE  
(By authority conferred on the public service commission by sections 4 and 6 of 1939  
PA 3, MCL 460.4 and 460.6, section 2 of 1969 PA 165, MCL 483.152, section 5 of 1919  
PA 419, MCL 460.55, sections 3, 9, and 231 of the executive organization act of 1965,  
1965 PA 380, MCL 16.103, 16.109, and 16.331, and section 2(12) of 1909 PA 300, MCL  
462.2(12), and Executive Reorganization Order Nos. 1996-2, 2003-1, 2008-4, and 2011-  
4, MCL 445.2001, 445.2011, 445.2025, and 445.2030)  
PART 1. GENERAL PROVISIONS  
R 460.2301 Definitions.  
Rule 1. As used in these rules:  
(a) “Approved by the commission” means that a commission order has been issued.  
(b) “British thermal unit” means the quantity of heat that must be added to 1  
avoirdupois pound of pure water to raise its temperature from 58.5 degrees Fahrenheit to  
59.5 degrees Fahrenheit under standard pressure. Standard pressure is 30 inches mercury  
at 32 degrees Fahrenheit or 14.73 pounds per square inch absolute and with acceleration  
due to gravity equal to 32.174 feet per second per second.  
(c) “Commission” means the Michigan public service commission.  
(d) “Cubic foot of gas” means either of the following:  
(i) For billing purposes, a standard cubic foot of gas is that quantity of dry gas that,  
at a temperature of 60 degrees Fahrenheit and an absolute pressure of 14.65 pounds per  
square inch, occupies 1 cubic foot. The commission may, however, approve a different  
absolute pressure base.  
(ii) For testing purposes, such as testing for heating value, a standard cubic foot of  
gas is that quantity of gas that, when saturated with water vapor at a temperature of 60  
degrees Fahrenheit and an absolute pressure of 14.73 pounds per square inch, occupies 1  
cubic foot.  
(e) “Customer” means an individual, firm, association, or corporation excluding  
other gas utilities, or any agency of the federal, state, county, or municipal government  
that purchases or otherwise receives gas or transportation services, or both, on the  
utility’s system.  
(f) “Hazardous condition” means any condition that the utility determines poses an  
immediate and serious threat to the health, safety, or welfare of a customer or the general  
public and that requires immediate action.  
(g) “Meter” means a device owned by a utility that is used in measuring a quantity  
of gas.  
(h) “Meter accuracy” means the volume that is measured by a meter as a percent of  
the actual volume that flowed through the meter as measured by a working standard.  
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(i) “Meter error” means a failure to accurately measure and record all of the natural  
gas used that is required by the applicable rate or rates.  
(j) “Mixed gas” means a gas that is produced by mixing natural gas with any of the  
following:  
(i) Air.  
(ii) Inert gas.  
(iii) Liquefied petroleum gas.  
(iv) Other flammable gas.  
(v) Substitute natural gas.  
(k) “Premises” means an individual piece of land or real estate that is not separated  
by public roads, streets, or alleys, including buildings and other appurtenances on that  
land or real estate.  
(l) “Potentially hazardous condition” means any condition that the utility determines  
has the potential to become a hazardous condition, but that does not require immediate  
action, including, but not limited to, any of the following:  
(i) Customer failure to permit the utility to perform inspections and maintenance on  
the utility’s facilities in or on the customer’s premises.  
(ii) Customer alterations or modifications of the utility’s facilities located in or on  
the customer’s premises.  
(iii) Customer construction of a structure or appurtenance near or over the main,  
service line piping, or meter set assembly so that the utility’s facilities are not in  
compliance with the provisions of R 460.20101 to R 460.20606 of the Michigan gas  
safety standards or the utility’s standards.  
(iv) Customer failure to correct or replace gas utilization equipment or gas fuel line  
piping that has been previously identified and classified as potentially hazardous by the  
utility.  
(m) “Rate book” means the assembled rate schedules, rules, regulations, and  
standard forms of the utility as filed with the commission and available on the  
commission’s website.  
(n) “Required access” means access that is necessary to conduct any of the  
following:  
(i) Routine inspections and maintenance.  
(ii) Meter readings of gas usage.  
(iii) Scheduled replacement, repairs, relocation, or disconnection of branch service  
lines or other changes with respect to service lines and meter assembly piping.  
(o) “Substitute natural gas” means gas that is interchangeable and compatible with  
natural gas and that is manufactured from carbon and hydrogen-bearing materials.  
(p) “Utility” means a person, firm, corporation, cooperative, association, or agency  
that is subject to the jurisdiction of the commission and that delivers or distributes and  
sells gas to the public for heating, power, or other residential, commercial, or industrial  
purposes.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2302 Application, intention, and interpretation of rules; utility rules and  
regulations.  
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Rule 2. (1) These rules apply to a gas utility that operates within the state of  
Michigan and that is subject to the jurisdiction of the commission.  
(2) These rules are intended to promote safe and adequate gas service to the public,  
to provide technical standards for uniform and reasonable practices by gas utilities, to  
encourage efficiency and economy, and to establish a basis for determining the  
reasonableness of such demands as may be made by the public upon gas utilities.  
(3) Questions that concern the application or interpretation of these rules and  
disagreements with respect to any service rules and regulations that are promulgated by a  
gas utility shall be referred to the commission for a ruling.  
(4) A utility shall adopt reasonable rules and regulations, subject to commission  
approval, governing its relations with customers. The rules and regulations must not be  
inconsistent with these rules and any other rules of the commission. A utility’s rules and  
regulations must constitute an integral part of the utility’s rate book.  
(5) Upon written request of a customer, utility, or on its own motion, the  
commission may waive any requirements of these rules when it determines the waiver  
will further the effective and efficient administration of these rules and is in the public  
interest.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2303 Rescission.  
Rule 3. R 460.891 to R 460.914, R 460.916, R 460.919, R 460.920, R 460.926,  
and R 460.927 of the Michigan Administrative Code, appearing on pages 6094 to  
6102, and 6104 of the 1954 volume of the Code, and pages 1070 and 1071 of the 1958  
Annual Supplement to the Code, are rescinded.  
History: 1979 AC.  
PART 2. RECORDS, REPORTS, AND OTHER INFORMATION  
R 460.2321 Retention of records.  
Rule 21. All records that are required to be made or maintained pursuant to these  
rules must be preserved by the utility for a period of time specified in R 460.2501 to R  
460.2582. If a time period is not specified in these  
rules or in R 460.2501 to R 460.2582, all records must be preserved by the utility for,  
at a minimum, 1 year after the records are completed.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2322 Location of records.  
Rule 22. Copies of all records required by these rules shall be kept within the  
boundaries of this state or at the administrative headquarters of the utility, and shall be  
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available at all reasonable times for examination by an authorized representative of the  
commission.  
History: 1979 AC.  
R 460.2323 Reports and records generally.  
Rule 23. (1) Volumetric data that is contained in any report must define the pressure,  
temperature, and water saturation upon which the data is based.  
(2) In addition to reports or records that are required to be filed with the commission  
pursuant to these rules, a utility shall provide the commission with a current list of the  
name, title, address, telephone number, and email address of the person who should be  
contacted in connection with all of the following:  
(a) General management duties.  
(b) Customer complaints that relate to operations.  
(c) Construction, maintenance, operations, and emergencies during office and  
nonoffice hours for each major operating headquarters.  
(d) Meter tests and repairs.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2324 Security reporting.  
Rule 24. (1) To inform the commission regarding matters that may affect the  
security or safety of persons or property, whether public or private, a utility must do both  
of the following:  
(a) Provide a written or oral annual report, individually or jointly with other utilities,  
to designated members of the commission staff regarding the utility’s cybersecurity  
program and related risk planning. This report on the threat assessment and preparedness  
strategy must contain all of the following information:  
(i) An overview of the program describing the utility’s approach to cybersecurity  
awareness and protection.  
(ii) A description of cybersecurity awareness training efforts for the utility’s staff  
members, specialized cybersecurity training for cybersecurity personnel, and  
participation by the utility’s cybersecurity staff in emergency preparedness exercises in  
the previous calendar year.  
(iii) An organizational diagram of the utility’s cybersecurity organization, including  
positions and contact information for primary and secondary cybersecurity emergency  
contacts.  
(iv) A description of the utility’s communications plan regarding unauthorized  
actions that result in loss of service, financial harm, or breach of sensitive business or  
customer data, including the utility’s plan for notifying the commission and customers.  
(v) A redacted summary of any unauthorized actions that resulted in material loss of  
service, financial harm, or breach of sensitive business or customer data, including the  
parties that were notified of the unauthorized action and any remedial actions undertaken.  
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(vi) A description of the risk assessment tools and methods used to evaluate,  
prioritize, and improve cybersecurity capabilities, including work completed pursuant to  
R 460.2345.  
(vii) General information about current emergency response plans regarding  
cybersecurity incidents, domestic preparedness strategies, threat assessments, and  
vulnerability assessments.  
(b) In addition to the information required under subdivision (a) of this subrule, an  
investor-owned public utility must include in its annual report to the Michigan public  
service commission an overview of major investments in cybersecurity during the  
previous calendar year and plans and rationale for major investments in cybersecurity  
anticipated for the next calendar year.  
(2) As soon as reasonably practicable and prior to any public notification, a utility  
must orally report the confirmation of a cybersecurity incident to a designated member of  
the commission staff and to the Michigan fusion center, unless prohibited by law or court  
order or instructed otherwise by official law enforcement personnel, if any of the  
following occurred:  
(a) A person intentionally interrupted the production, transmission, or distribution of  
natural gas.  
(b) A person extorted money or other things of value from the utility through a  
cybersecurity attack.  
(c) A person caused a denial of service in excess of 12 hours.  
(d) A security breach, as defined by section 3(b) of the identity theft protection act,  
2004 PA 452, MCL 445.63(b), prior to public and customer notification.  
(e) At the utility’s discretion, any other cybersecurity incident, attack, or threat that  
the utility deems notable, unusual, or significant.  
(3) As used in subrule (2) of this rule, “person” means any individual, firm,  
corporation, educational institution, financial institution, governmental entity, or legal or  
other entity.  
(4) As used in subrule (2)(c) of this rule, “denial of service” means, for a utility, a  
successful attempt to prevent a legitimate user from accessing electronic information  
made accessible by the utility or by another party on the behalf of the utility.  
History: 2020 MR 17, Eff. Sept. 3, 2020.  
PART 3. SERVICE REQUIREMENTS  
R 460.2331 Sale of gas.  
Rule 31. (1) All gas that is sold by a utility must be on the basis of meter  
measurement, unless otherwise approved by the commission.  
(2) The utility shall provide the terms and conditions of service available to  
prospective customers upon request.  
(3) If gas is supplied and metered to a customer at a nominal delivery pressure of  
0.25 pounds per square inch gauge, then, for billing purposes, both of the following  
provisions apply:  
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(a) The gas volume that is registered by the meter is assumed to be measured at  
standard billing conditions as defined in R 460.2301(d)(i), regardless of the actual  
temperature of the gas or actual atmospheric pressure. All meters that are to operate at  
ambient outdoor conditions must be equipped with a temperature-compensating device.  
(b) If the billing pressure base is 14.65 pounds per square inch absolute, then the  
atmospheric pressure is assumed to be 14.4 pounds per square inch absolute. If the  
commission has approved a different billing pressure base, then the assumed atmospheric  
pressure is equal to the difference between such absolute billing pressure base and 0.25  
pounds per square inch.  
(4) If gas is supplied to a customer through a low-pressure distribution system such  
that a service regulator is not used before metering, then, for billing purposes, the gas  
must be assumed to be supplied and metered at 0.25 pounds per square inch gauge. The  
low-pressure system must be operated so that the gauge pressure at the outlet of the meter  
must be maintained within a range of 3 inches water column minimum to a maximum of  
14 inches water column. However, delivery to the customer may be as high as 18 inches  
water column if the pressure to the gas utilization equipment is regulated to not more than  
14 inches water column. A utility may implement different standards for operating its  
low-pressure system if those standards are approved by the commission.  
(5) If gas is supplied and metered to a customer at a nominal delivery pressure of  
more than 0.25 pounds per square inch gauge, then, for billing purposes, all of the  
following provisions apply:  
(a) The gas volume that is measured by the meter must be corrected to standard  
billing conditions as defined in R 460.2301(d)(i).  
(b) Gas volume corrections for temperature must be made pursuant to Charles’ law.  
Gas volume corrections for pressure must be made pursuant to Boyle’s law. Gas volume  
corrections for supercompressibility must be made pursuant to either of the following  
publications, both of which are adopted by reference in R 460.2344:  
(i) “Manual for the Determination of Supercompressibility Factors, PRCI Project  
NX-19” as adopted by reference in R 460.2344.  
(ii) “American Gas Association (AGA) Report No. 8, Part 1, “Thermodynamic  
Properties of Natural Gas and Related Gases, DETAIL and GROSS Equations of State.”  
(2017) AGA Catalog No. XQ1704-1 as adopted by reference in R 460.2344.  
(c) If the pressure at which the gas is metered is established on a gauge basis rather  
than an absolute basis, then the absolute pressure at which the gas is metered must be  
inferred by summing the gauge pressure and either the actual atmospheric pressure or a  
reasonable estimate thereof or an atmospheric pressure that is filed with, and approved  
by, the commission.  
(d) If a pressure-compensating device is used with the meter, the device must be  
calibrated using the actual atmospheric pressure or a reasonable estimate thereof.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2332 Service line tariffs.  
Rule 32. Within 30 days after a company commences operating as a gas utility, the  
utility shall file its service line tariffs for commission approval. These tariffs must  
constitute an integral part of the utility’s rate book.  
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History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2333 Main extension tariffs.  
Rule 33. Within 30 days after a company commences operating as a gas utility, the  
utility shall file its main extension tariffs for commission approval. These tariffs must  
constitute an integral part of the utility’s rate book.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2334 Temporary service.  
Rule 34. If a utility renders temporary service to a customer for a period not  
exceeding 2 years or for the duration of a particular construction project using such  
temporary service, in addition to the charges for gas used during such service, the utility  
may require the customer to bear all of the cost of installing, removing, and providing  
equipment of facilities for such temporary service, less the salvage value of any  
equipment or facilities retained by the utility at the conclusion of the temporary service.  
History: 1979 AC.  
R 460.2335 Interruptions of service.  
Rule 35. (1) This rule does not apply to service interruptions that result from a  
utility’s shutoff of service due to nonpayment of bills, unauthorized use of gas service, or  
pursuant to the provisions of R 460.2371 and R 460.2373.  
(2) A utility shall make a reasonable effort to prevent interruptions of service and,  
when such interruptions occur, shall endeavor to reestablish service with the shortest  
possible delay consistent with the safety of its customers, its employees and others  
engaged in work for the utility, and the general public. If service is necessarily  
interrupted for the purpose of working on the distribution system or plant equipment, it  
must be done at a time that causes the least inconvenience to customers, and those  
customers who may be seriously affected shall be notified in advance.  
(3) If the supply of gas diminishes to the point where continuous service to  
customers is threatened, the utility may limit or shut off service to its customers pursuant  
to curtailment procedures approved by the commission.  
(4) A utility shall keep records of reportable outages on its entire system or in major  
divisions or operating districts of its system. The records must include a statement of the  
time, duration, and cause of the interruption. A utility shall report interruptions of  
service, as required by R 460.20101 to R 460.20606 and shall periodically make an  
analysis of the records to determine steps to be taken to prevent the recurrence of these  
interruptions.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
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PART 4. ENGINEERING  
R 460.2341 Gas facilities; construction and installation.  
Rule 41. (1) Gas facilities of a utility must be constructed and installed pursuant to  
accepted engineering practices in the gas industry and R 460.20101 to R 460.20606 to  
ensure, to the extent reasonably practicable, continuity of service, uniformity in the  
quality of service provided, and the safety of persons and property.  
(2) All new meters must conform to 1 of the following standards adopted by  
reference in R 460.2344:  
(a) American National Standards Institute (ANSI) B109.1-2019 for Diaphragm-  
Type Gas Displacement Meters (Under 500 Cubic Feet per Hour Capacity).  
(b) ANSI B109.2-2000 (R2008) for Diaphragm-Type Gas Displacement Meters  
(500 Cubic Feet per Hour Capacity and Over).  
(c) ANSI B109.3-2019 for Rotary Type Gas Displacement Meters.  
(d) AGA Report No. 3, Orifice Metering of Natural Gas Part 2: Specifications and  
Installation Requirements.  
(e) AGA Report No. 7, Measurement of Gas by Turbine Meter.  
(f) AGA Report No. 9, Measurement of Gas by Multipath Ultrasonic Meters.  
(g) AGA Report No. 11, Measurement of Natural Gas by Coriolis Meter, Second  
Edition.  
History: 1979 AC; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2342 Rescinded.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2343 Rescinded.  
History: 1979 AC; 1993 AACS.  
R 460.2344 Adoption of standards by reference.  
Rule 44. (1) The publications and standards listed in this rule are adopted by  
reference and are a part of these rules. Publications identified as published by a specific  
organization are available from the organization at the address specified in this rule. All  
prices are current at the time of the adoption of these rules. The commission also has  
copies of the publications available for inspection and distribution at its offices located at  
7109 W. Saginaw Highway, Lansing, Michigan 48917 at a cost of 10 cents per page  
unless otherwise specified in this rule.  
(2) The numbers in parentheses following the publications adopted by reference  
indicate the applicable editions.  
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(a) The current edition of the Michigan gas safety standards, which is available  
commission. $61.49.  
(b) The following publications of the American Gas Association (AGA), available  
from the American Gas Association, 400 North Capitol Street, NW, Suite 450,  
Washington, DC 20001, 202-824-7000, www.aga.org:  
(i) “Manual for the Determination of Supercompressibility Factors, PRCI Project  
NX-19,” (1970) AGA Catalog No. L00340. $149.00.  
(ii) AGA Report No. 8, Part 1, “Thermodynamic Properties of Natural Gas and  
Related Gases, DETAIL and GROSS Equations of State.” (2017) AGA Catalog No.  
XQ1704-1. $320.00.  
(iii) AGA Report No. 3, “Orifice Metering of Natural Gas Part 1: General Equations  
and Uncertainty Guidelines.” (2013, includes errata) AGA Catalog No. XQ1201.  
$168.00.  
(iv) AGA Report No. 3, Part 2, “Orifice Metering of Natural Gas and Other Related  
Hydrocarbon Fluids – Concentric, Square-edged Orifice Meters, Specifications and  
Installation Requirements.” (2017, includes errata) AGA Catalog No. XQ1601. $168.00.  
(v) AGA Report No. 3, “Orifice Metering of Natural Gas Part 3: Natural Gas  
Applications.” (2013) AGA Catalog No. XQ1304. $148.00.  
(vi) AGA Report No. 3, “Orifice Metering of Natural Gas Part 4: Background,  
Development, Implementation Procedures.” (1992) AGA Catalog No. XQ9211. $148.00.  
(vii) American National Standards Institute (ANSI) B109.1-2019, “Diaphragm-Type  
Gas Displacement Meters, Under 500 Cubic Feet per Hour Capacity.” AGA Catalog No.  
X61902. $110.00.  
(viii) ANSI B109.2-2000 (R2008), “Diaphragm-Type Gas Displacement Meters,  
500 Cubic Feet per Hour Capacity and Over.” AGA Catalog No. XQ0009. $110.00.  
(ix) ANSI B109.3-2019, “Rotary Type Gas Displacement Meters.” (2000) AGA  
Catalog No. XM1901. $110.00.  
(x) AGA Report No. 7, “Measurement of Gas by Turbine Meter.” (2006) AGA  
Catalog No. XQ0601. $352.00.  
(xi) AGA Report No. 9, “Measurement of Gas by Multigraph Ultrasonic Meters.”  
(2017) AGA Catalog No. XQ1705. $400.00.  
(xii) AGA Report No. 11, “Measurement of Natural Gas by Coriolis Meter, Second  
Edition.” (2013) AGA Catalog No. XQ1301. $440.00.  
(xiii) National Fuel Gas Code. (2018) AGA Catalog No. Z223118. $60.00.  
(c) The following publications of the American Society for Testing and Materials  
(ASTM) International available from ASTM International, 100 Barr Harbor Drive, PO  
Box C700, West Conshohocken, PA, 19428, 610-832-9585, www.astm.org:  
(i) ASTM D1826-94, “Standard Test Method for Calorific (Heating) Value of Gases  
in Natural Gas Range by Continuous Recording Calorimeter.” (2017) ASTM Catalog  
No. D-1826. $46.00.  
(ii) ASTM D1945-14, “Standard Test Method for Analysis of Natural Gas by Gas  
Chromatography.” ASTM Catalog No. D-1945. $52.00.  
(iii) ASTM D3588-98, “Standard Practice for Calculating Heating Value,  
Compressibility Factor, and Relative Density of Gaseous Fuels.” (2017) ASTM Catalog  
No. D-3588. $46.00.  
Page 9  
(d) The following publications of the American Society for Quality (ASQ) available  
from American Society for Quality, PO Box 3005, Milwaukee, WI 53201, 800-248-1946,  
www.asq.org:  
(i) ANSI/ASQ Z1.9-2003 (R2018), “Sampling Procedures and Tables for Inspection  
by Variables for Percent Nonconforming.” $149.00.  
(ii) ANSI/ASQ Z1.4-2003 (R2018), “Sampling Procedures and Tables for  
Inspection by Attributes.” $159.00.  
(e) American Petroleum Institute (API) Standard 1164 Ed. 2 (2009/R2016),  
“Pipeline SCADA Security,” available from API Publishing Services, 1220 L Street,  
NW, Washington DC 20005. $146.00.  
History: 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2345 Security standards.  
Rule 45. Unless otherwise approved by the commission, all utilities utilizing  
supervisory control and data acquisition systems shall implement API Standard 1164 Ed.  
2 (2009/R2016), as adopted by reference in R 460.2344.  
History: 2020 MR 17, Eff. Sept. 3, 2020.  
PART 5. METERS METERING EQUIPMENT INSPECTIONS AND TESTS  
R 460.2351 Meters and associated metering devices; inspections; tests; and  
records.  
Rule 51. Inspections and tests of meters and associated metering devices must be  
made by, or on behalf of, each utility as follows:  
(a) A meter or an associated metering device that is not included as a part of the  
meter, or both, must be inspected and tested before being placed in service, and the error  
must not be more than 1.0%.  
(b) A meter or an associated metering device, or both, must be tested after it is  
removed from service. These tests must be made before the meter or associated metering  
device is adjusted, repaired, or retired.  
(c) A repaired meter or a meter that is removed from service must be leak-tested  
before being returned to service, subject to the following requirements:  
(i) If tested in the field, a meter must be tested at the actual meter operating pressure  
of the system.  
(ii) If tested in the shop, a meter must be subjected to an internal pressure test of, at a  
minimum, 3.0 pounds per square inch gauge pressure. In addition, any meter that will  
operate above 3.0 pounds per square inch gauge pressure must be so marked on the meter  
and must be subjected to 1 of the following tests:  
(A) An internal pressure test of, at a minimum, the manufacturer’s rated operating  
pressure.  
(B) An internal pressure test at 10% above the maximum operating pressure to  
which the meter could be subjected.  
Page 10  
(C) Any suitable test that is approved by the commission.  
(iii) During the pressure test, the meter must be checked for leaks by 1 of the  
following tests:  
(A) Immersion test.  
(B) Soap test.  
(C) Pressure drop test of a type that is approved by the commission.  
(d) As part of its rate book, a utility shall file, for commission approval, a statement  
of its policy with regard to testing meter accuracy upon a customer’s request. In the  
absence of a filed policy approved by the commission, the utility shall adhere to both of  
the following provisions:  
(i) A utility shall test meter accuracy upon the request of a customer if the customer  
does not request a test more than once every 2 years and if the customer agrees to accept  
the results of the test as the basis for determining the difference claimed. A charge must  
not be made to the customer for the first test in any 5-year period, but if subsequent tests  
during the same period, for the same customer, show the meter to be within the allowable  
limits of accuracy, the utility may charge the customer an amount for subsequent tests  
which is uniform and which does not exceed the utility’s direct cost thereof, plus a  
reasonable charge for administrative overhead. The customer may be present at the test if  
he or she makes a request before the test.  
(ii) A written report must be made to the customer by the utility. The report must  
state the results of the test. A record of the test must be kept by the utility.  
(e) A utility shall make periodic tests of meters, associated devices, and instruments  
to ensure their accuracy. The tests must be conducted according to the following  
schedule, unless otherwise approved by the commission. A utility may test meters more  
frequently than provided in the following schedule without commission approval:  
(i) Positive displacement diaphragm-type meters that have capacities of less than  
500 cubic feet per hour, not to exceed 123 months.  
(ii) Positive displacement diaphragm-type meters that have capacities over 500 cubic  
feet per hour, not to exceed 87 months.  
(iii) Rotary meters that have capacities of less than 15,000 cubic feet per hour, which  
may be tested in place, not to exceed 51 months.  
(iv) Rotary meters that have capacities of 15,000 cubic feet per hour or more, which  
may be tested in place, not to exceed 27 months.  
(v) Other meter types, such as turbine, Coriolis, 4-Path or greater ultrasonic, or other  
metering technology, which may be tested in place when possible, not to exceed 27  
months.  
(vi) Orifice meters, 2 times per year with intervals not to exceed 7.5 months.  
(vii) Gas instruments, such as base volume, base pressure, and base temperature-  
correcting devices, must be checked for calibration at intervals that correspond to the  
schedule for their associated meters. The testing interval must not exceed 51 months.  
(viii) Test bottles, deadweight testers, certified test meters, not to exceed 123  
months.  
(ix) Meter testing systems must be calibrated when first installed and after  
alterations, damages, or repairs that might affect accuracy. To ensure that the accuracy of  
a meter testing system is maintained on a continuous basis, a daily leakage test must be  
made and a weekly accuracy test with a comparison meter of known accuracy must be  
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made. If the test results differ by more than plus or minus 0.5% from the comparison  
meter, the cause of the error must be determined and necessary corrections must be made  
before the system is reused. The comparison meter must be checked at an interval of 1  
year not to exceed 13 months.  
(f) Utilities shall maintain records of meters that have been tested during the  
preceding calendar year and shall make this information available to the commission  
upon request. The record must contain all of the following information for each meter  
tested:  
(i) Set year.  
(ii) Type of case.  
(iii) Manufacturer.  
(iv) Customer class, either commercial and industrial or residential.  
(v) Results of the meter test.  
(vi) Whether the meter was retired and if so the reasons for the retirement.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2351a Statistical quality sampling program for diaphragm-type meters.  
Rule 51a. (1) A utility shall comply with the provisions of R 460.2351, except that a  
utility that receives approval from the commission may adopt the requirements of this  
rule for statistical sampling and quality control of in-service diaphragm meters.  
Statistical sampling and quality control must be supervised by an individual trained in  
statistical sampling techniques.  
(2) A utility may use any of the following statistical quality control programs for  
meter testing, as adopted by reference in R 460.2344:  
(a) ANSI B109.1-2019, “Diaphragm-Type Gas Displacement Meters, Under 500  
Cubic Feet per Hour Capacity.”  
(b) ANSI B109.2-2000 (R2008), “Diaphragm-Type Gas Displacement Meters, 500  
Cubic Feet per Hour Capacity and Over.”  
(c) ANSI/ASQ Z1.9-2003 (R2018), “Sampling Procedures and Tables for  
Inspection by Variables for Percent Nonconforming.”  
(d) ANSI/ASQ Z1.4-2003 (R2018), “Sampling Procedures and Tables for  
Inspection by Attributes.”  
(3) A utility may use an alternative statistical quality sampling program if approved  
by the commission. An application to use an alternative program must include all of the  
following information:  
(a) A description of the sampling program that must include all of the following:  
(i) The type or types of meters subject to the sampling plan.  
(ii) The frequency of testing.  
(iii) The procedures to be used for the sampling.  
(iv) The meter test method to be used.  
(v) The accuracy of the testing and of the sampling plan.  
(b) An explanation of the reason or reasons for the requested sampling plan.  
(c) An analysis that demonstrates that, with respect to assuring the accuracy of the  
meters tested, the requested sampling program is at least as effective as the standards  
listed in subrule (2) of this rule.  
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(4) Meters for quality control sampling must be separated into homogenous groups  
by year set and may be further separated by manufacturer, capacity rating, model, case  
type, diaphragm material, year manufactured, or other distinguishing characteristics.  
When 1 or more groups established are believed to be too small for practical quality  
control sampling, they may be combined with another group of similar operating  
characteristics to establish a larger sampling base. Combined groups must have sample  
size and acceptance-rejection numbers based on the combined total of meters. Samples  
must be drawn by a random method that ensures each meter in the group has an equal  
chance of being selected.  
(5) All meter groups, or combined meter groups, must be subject to acceptance or  
rejection on the basis of the statistical results unless it becomes obvious that the rejected  
meters are predominantly from 1 identifiable subgroup which may be shown by test data  
to have been affected by location, age, or other common factors. If this result should  
occur, the identifiable subgroup may be separated and the remaining meters treated as a  
new combined group with appropriate sample size and acceptance-rejection numbers.  
(6) A meter removed from a customer’s premises and tested as part of any business  
practice not related to the statistical quality control program must be included only in the  
program’s sample if the meter is randomly selected according to subrule (4) of this rule.  
(7) Not later than March 1 of each year, utilities shall file a report of the meters that  
have been tested during the preceding calendar year. The report must include separate  
sections addressing results for meters tested as part of the statistical quality control  
program and meters tested as part of routine meter removals or exchanges. The report  
must detail both of the following:  
(a) All of the following meter characteristics:  
(i) Set year.  
(ii) Type of case.  
(iii) Manufacturer.  
(iv) Type of diaphragm.  
(v) Revenue classification, either commercial and industrial or residential.  
(b) The number of meters in each meter class tested and found within the norm and  
within each 1% variance from norm between 94% accuracy and 106% accuracy. Meters  
that are slower than 94% and faster than 106% must each be grouped separately. Meters  
that are determined to be nonregistering must be reported to either have been repaired,  
tested, and returned to the field, or retired.  
History: 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2352 Rescinded.  
History: 1979 AC; 1984 AACS; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2353 Retirement of meters.  
Rule 53. (1) Meters must be retired from service whenever abnormal conditions  
affecting accuracy cannot be corrected for economic or other reasons. Examples of such  
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conditions are basic defects due to manufacture, design, or excessive damage. Meters  
may also be retired due to obsolescence, unavailability of repair parts, or other reasons.  
(2) Notwithstanding the provisions of any other rule, meters that are found to be  
overregistering must be repaired or replaced within 6 months of the discovery of the error  
unless a different period is approved by the commission.  
History: 1979 AC; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2354 Accuracy of metering equipment; tests; standards.  
Rule 54. (1) A utility shall use the applicable provisions of the standards adopted by  
reference in R 460.2344 as criteria of accepted practice in testing meters.  
(2) Metering equipment must be tested by comparison with the standards that are  
adopted by reference in R 460.2344.  
(3) A gas service meter that is repaired or removed from service for any cause must,  
before installation, be tested and adjusted to be correct within 1% fast or 1% slow.  
(4) Every diaphragm-type gas meter must be tested before installation and adjusted,  
if required, to a meter accuracy of 100% plus or minus 1% at a low flow rate and at a  
high flow rate so that the numerical difference between the meter accuracy at these 2  
flow rates is not more than 1 percentage point. A low flow rate is a flow at 20% to 50%  
of the rated capacity of the meter. A high flow rate is a flow at 80% to 120% of the rated  
capacity of the meter. The average meter accuracy of a diaphragm-type meter must be  
defined as 1/2 the sum of the meter accuracy at the low flow test and at the high flow test.  
(5) All recording-type meters or associated instruments that have a timing element  
that serves to record the time at which the measurement occurs for billing purposes must  
be adjusted at intervals of not more than 2 years so that the timing element is not in error  
by more than plus or minus 4 minutes in 24 hours, under laboratory conditions, as set  
forth in ANSI B109.1-2019, “Diaphragm Type – Gas Displacement Meters, Under 500  
Cubic Feet per Hour Capacity”, which is adopted by reference in R 460.2344, or by more  
than plus or minus 10 minutes in 24 hours under field conditions.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2355 Meter shop; design; meter testing system; standards; handling;  
calibration cards; calibrated orifices.  
Rule 55. (1) A utility shall maintain or designate a meter shop within Michigan for  
the purpose of inspecting, testing, and repairing meters. The shop must be open for  
inspection by authorized representatives of the commission at all reasonable times. A  
utility may obtain approval from the commission to have its meters tested outside of  
Michigan upon showing, to the satisfaction of the commission, that the meter test  
facilities so utilized are in compliance with these rules. Records of test results must be  
maintained in Michigan or the administrative headquarters of the utility.  
(2) The area within the meter shop that is used for the testing of meters must be  
designed so that the meters and meter-testing equipment are protected from drafts and  
excessive changes in temperature. The meters to be tested must be stored in such a  
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manner that the temperature of the meters is substantially the same as the temperature of  
the prover.  
(3) A utility shall own and maintain, or have access to, a meter-testing system  
(working standard) of an approved type, subject to all of the following provisions:  
(a) Means must be provided to maintain the temperature of the liquid in a meter-  
testing system at substantially the same level as the ambient temperature in the prover  
area.  
(b) The meter-testing system must be maintained in good condition and in correct  
adjustment so that it is capable of determining the accuracy of any service meter to plus  
or minus 0.5%.  
(c) A utility may use a properly calibrated test meter or transfer prover or may use a  
properly designed flow prover for testing meters.  
(4) Meter-testing systems (working standards) must be checked by comparison with  
a secondary standard. Both of the following provisions must be complied with:  
(a) At least once every 5 years, bell and flow provers must be checked with a 1-  
cubic foot bottle or must be calibrated by dimensional measurement or any other test that  
is approved by the commission. The accuracy of the secondary standard that is used must  
be traceable to the National Institute of Standards and Technology.  
(b) At least once every 10 years, rotary displacement transfer provers must be  
checked with a standard that has its calibration traceable to the National Institute of  
Standards and Technology or must be checked by any other suitable test that is approved  
by the commission.  
(5) Extreme care must be exercised in the use and handling of standards to ensure  
that their accuracy is maintained.  
(6) Each standard must have a certificate or calibration card which must be duly  
signed and dated and which must record the corrections that were required to compensate  
for errors found on the last test.  
(7) A utility shall have properly calibrated orifices to achieve the rates of flow  
required to test the meters on its system.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2356 Pressure measurement standards.  
Rule 56. (1) For its working pressure measurement standards, a utility shall have  
manometers, laboratory-quality indicating pressure gauges, field-type deadweight  
pressure gauges, or any other instruments that have an accuracy error of not more than  
1/2 of 1% of full scale, which shall be used to test the indicating and recording  
pressure gauges that are used in determining the pressure on the utility's system.  
(2) For its secondary pressure measurement standards, a utility shall own, or  
have access to, a pressure-testing instrument that has an accuracy error of not more than  
1/10 of 1% of full scale, which shall be used to verify the accuracy of its working  
pressure measurement standards. An instrument that is used as a secondary pressure  
measurement standard shall be maintained in an accurate condition.  
History: 1979 AC; 1993 AACS.  
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R 460.2357 Records; meter tests.  
Rule 57. (1) A utility shall maintain records of the last 2 tests made on any meter.  
The record of the meter test made at the time of the meter's retirement shall be  
maintained for a minimum of 3 years.  
(2) Test records shall include the following information:  
(a) The date and reason for the test.  
(b) The index reading of the meter at the time of removal from the customer's  
premises.  
(c) The meter accuracy "as found."  
(3) If the test of the meter is made by using a test meter, transfer prover, or flow  
prover, the utility shall retain, as test records, all data taken at the time of the test in  
complete form to permit the checking of the test methods and the calculations.  
History: 1979 AC; 1993 AACS.  
R 460.2358 Records; meter and associated metering device data.  
Rule 58. A utility shall maintain records of the following data, where applicable,  
for each meter or associated metering device, or both, until retirement:  
(a) Descriptive data, manufacturer, identification number, type, capacity,  
multiplier, and constants.  
(b) The dates of installation and removal from service, together with the location of  
current and previous installation.  
History: 1979 AC.  
PART 6. BILL ADJUSTMENT; METER ACCURACY  
R 460.2361 Rescinded.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2362 Determination of adjustment.  
Rule 62. (1) If the date that the period of inaccurate meter registration began can be  
determined, that date must be the starting point for calculating an adjustment pursuant to  
the provisions of R 460.115.  
(2) If the date that the period of inaccurate meter registration began cannot be  
determined, it must be assumed that the inaccuracy existed for a period equal to 1/2 of the  
time elapsed since the meter was last installed or tested.  
(3) The adjustment must be made on the basis of actual monthly consumption, if  
possible. Otherwise, the average monthly consumption that is determined from the most  
recent 36 months’ consumption data must be used.  
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History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2363 Refunds.  
Rule 63. Refunds shall be made to the 2 most recent customers who received service  
through the meter found to be registering inaccurately. In the case of a previous customer  
who is no longer a customer of the utility, a notice of the amount of the refund shall be  
mailed to his or her last known address and the utility shall, upon demand made within 3  
months, refund the amount.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2364 Rescinded.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2365 Consumption data records.  
Rule 65. Records of all consumption data and other data necessary for the  
administration of adjustment of bills shall be maintained for a minimum period of 36  
months.  
History: 1979 AC.  
PART 7. SHUTOFF OF SERVICE  
R 460.2371 Conditions for establishing gas service; liability; notice and record of  
inability to establish service; refusal of service to customer using other gaseous fuel;  
exception; service quality.  
Rule 71. (1) A utility shall establish gas service to a customer’s premises in  
compliance with the Michigan gas safety standards.  
(2) The utility shall not be liable for the installation, maintenance, or use of piping or  
gas utilization equipment that is owned by the customer, nor be held liable for any  
continuing duty of inspection of piping or equipment.  
(3) If the condition of the customer’s fuel line is such that service cannot be  
established, the utility shall notify the customer, in writing, of the reason or reasons that  
service was not established.  
(4) A record must be kept by the utility of all cases where refusal to establish service  
is made. The record must provide all of the following information:  
(a) The name of the customer.  
(b) The address or location of the premises.  
(c) The date of the test.  
(d) The name of the service person.  
(e) All changes or rearrangements recommended.  
Page 17  
(5) Except in certain commercial and industrial applications that require a standby  
fuel that is authorized by the utility, the utility shall have the authority to refuse gas  
service to a customer that uses another gaseous fuel, such as liquefied petroleum gas, in  
the same building.  
(6) A utility shall have a meter reading factor of 85% or more for meters requiring  
billing reads within the meter reading period pursuant to the approved tariff, including  
customer reads.  
(7) If there is an existing main at a requesting address, a utility shall complete 90%  
or more of its new service installations within 15 business days of customer payment per  
tariff requirements and site readiness, or by a later date that is mutually agreed upon  
between the utility and customer.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2372 Gas facilities hazard.  
Rule 72. When a utility acquires knowledge that a customer's action has caused a  
hazardous condition to exist with respect to a gas facility, the utility shall initiate the  
following action depending on the facility that is involved:  
(a) For a utility's facilities, the utility shall correct the condition at the expense of  
the customer or shut off service to the customer.  
(b) For a customer's facilities, the utility shall correct the condition at the expense of  
the customer, if such action is authorized by the utility's service policy and if the  
customer consents. Otherwise, the utility shall shut off service to the customer until  
the condition has been corrected.  
History: 1979 AC; 1993 AACS.  
R 460.2373 Shutoff of service.  
Rule 73. Under any of the following conditions, gas service may be shut off by the  
utility:  
(a) A hazardous condition exists. In this instance, gas service may be shut off  
without prior notification.  
(b) A potentially hazardous condition exists. In this instance, gas service may be  
shut off after providing the customer with written notice of shutoff by first class mail at  
least 10 days before the shutoff is scheduled to occur.  
(c) Refusal of required access. In this instance, gas service may be shut off after  
providing the customer with written notice of the shutoff by first class mail at least 10  
days before the shutoff is scheduled to occur.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2374 Rescinded.  
History: 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
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PART 8. GAS QUALITY  
R 460.2381 Gas purity.  
Rule 81. (1) Gas that is distributed by a utility to a customer must not contain more  
than 0.3 grains of hydrogen sulfide or more than 20 grains of total sulfur per 100 cubic  
feet, including the sulfur in any hydrogen sulfide.  
(2) Gas that is distributed by a utility to a customer must not contain flammable  
liquids in quantities that interfere with the normal operation of the customer’s equipment.  
(3) Gas that is distributed by a utility to a customer must not contain more than 2%  
carbon dioxide or 5 parts per million oxygen.  
(4) Gas that is distributed by a utility to a customer must not contain water in excess  
of 7 pounds per million cubic feet.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2382 Heating value; authorized variations.  
Rule 82. (1) The heating value of substitute natural gas and mixed gas must be  
considered as being under the control of the utility. The average heating value on 1 day  
must not be more than or less than the standard total heating value range set forth in the  
utility’s rules. A utility shall not add air to a gas stream if this results in a heating value  
that is below 1,000 British thermal units per standard cubic foot.  
(2) The average monthly heating value of gas that is supplied by a utility shall be  
1,025 British thermal units per standard cubic foot, plus or minus 75 British thermal  
units. A greater variation may be approved by the commission upon a showing by the  
utility that the variation will not adversely affect the efficient and satisfactory operation  
of its customers’ gas utilization equipment.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2383 Heating value records; location and accuracy of measuring  
equipment; frequency of heating value determination.  
Rule 83. (1) A utility shall maintain records of the heating value of the gas it  
distributes. Heating value test records must be preserved for a minimum of 6 years. A  
utility shall utilize either the industry standards that are adopted by reference in R  
460.2344(d) or other standards that are approved by the commission for heating value  
determination methods.  
(2) Heating value measuring equipment must be installed in suitably located testing  
stations.  
(3) The accuracy of all heating value measuring equipment and the method of  
making heating value tests must meet the industry standards that are adopted by reference  
in R 460.2344(d) or must otherwise be approved by the commission. Recording  
equipment must be tested, at a minimum, annually.  
Page 19  
(4) The utility shall determine the heating value of substitute natural gas and mixed  
gas at a minimum of twice a day and shall make the tests during the periods of the a.m.  
and p.m. peak demands.  
(5) The utility shall determine the heating value of gas at least once a month. A  
utility that sells gas subject to a thermal adjustment shall determine the heating value at  
least once a day.  
History: 1979 AC; 1993 AACS; 2020 MR 17, Eff. Sept. 3, 2020.  
R 460.2384 Rescinded.  
History: 1979 AC; 1993 AACS.  
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