Within 30 days of the effective date hereof, each company distributing natural gas shall advise this commission, by a letter signed by a responsible official of the company, of the manner in which the specific gravity of said gas is determined at or before each respective source of the gas. Each company's statement shall include the locations where said determinations are made, the name of the transmission corporation or company making said determinations at each location, information indicating that the samples tested in said determinations at each location are representative of the gas distributed by the company, the types of specific gravity equipment used in said determinations at each location and a summary of the procedure employed at each location for making said determinations and verifying their accuracy.
(a) Determination for metering purposes.
(1) Where a company distributes natural gas that has had its specific gravity determined by the relevant transmission corporation in a manner adequate for orifice and other types of velocity metering at a testing station fully complying with the provisions of subdivision (b) of section 229.50, and section 229.51, with its total chemical composition unchanged from the location of specific gravity determination to the location of consumption, specific gravity equipment need not be installed in its testing station testing said gas provided that said company is periodically supplied with reports regarding the specific gravity of the gas. Said reports shall also include suitable identifying data such as the source of each gas sample tested, the date that it was taken, the date, method and location of test, etc. and sufficient information to demonstrate that each sample is representative of the gas delivered to the company, that its specific gravity has been determined in a manner adequate for orifice and other types of velocity metering and that the equipment used to determine the specific gravity of the gas is periodically adjusted and calibrated in accordance with the provisions of subdivision (a) of section 229.21.
(2) Where a company distributes gas that has not had its specific gravity determined in a manner adequate for orifice and other types of velocity metering at a testing station fully complying with the provisions of subdivision (b) of section 229.50, and section 229.51 or that does not have its total chemical composition unchanged from the location of specific gravity determination to the location of consumption, part of which is distributed to a consumer with an orifice or other type of velocity meter, said company shall
(i) provide each of its testing stations testing said gas required herein by subdivisions (a) through (d) of section 229.50 with a recording gravitometer fully complying and standardized, maintained, adjusted and calibrated in full compliance with the provisions therefor of the relevant effective code of the American Society for Testing Materials, the presently effective code being entitled "Standard Methods of Test for Specific Gravity of Gaseous Fuels (D 1070 52)" (the presently effective code hereinafter referred to as ASTM D 1070), and the recommendations therefor of pages 76 through 95 of Miscellaneous Publication M 177 of the National Bureau of Standards entitled "Tests of Instruments for the Determination, Indication, or Recording of the Specific Gravities of Gases" (hereinafter referred to as NBS M 177) and
(ii) operate said recording gravitometer likewise in full compliance with said codes.
(b) Automatic and manual determination. In each instance not described herein by subdivision (a), each company shall
(1) provide each of its testing stations required herein by subdivisions (a) through (d) of section 229.50 with specific gravity equipment fully complying and standardized, maintained, adjusted and calibrated in full compliance with the relevant provisions therefor of ASTM D 1070 and/or the relevant recommendations therefor of NBS M 177 and those of the manufacturer's instructions therefor that do not conflict with either ASTM D 1070 or NBS M 177 and
(2) operate said specific gravity equipment likewise in full compliance with said codes.