(a) Each distribution system supplied by more than one district pressure-regulating station must be equipped with telemetering or recording pressure gauges to indicate the gas pressure in the district.

(b) On distribution systems supplied by a single district pressure-regulating station, the operator shall determine the necessity of installing telemetering or recording gauges in the district, taking into consideration the number of customers supplied, the operating pressures, the capacity of the installation, and other operating conditions.

(c) For low-pressure distribution systems, the telemetering or recording pressure gauges are to be located at, or near each district regulator outlet and the probable locations of minimum pressures in each part of the system.

(d) The accuracy of each recording pressure gauge provided and maintained by each operator at the locations required herein shall be tested at intervals not exceeding 15 months, but at least once each calendar year. The results of the tests shall be recorded.

(e) Each chart removed from a recording pressure gauge shall be reviewed for indications of abnormally high or low pressure. If there are indications of abnormally high or low pressure, the regulator and the auxiliary equipment must be inspected and the necessary measures taken to correct any unsatisfactory operating conditions.

(f) Each chart removed from a recording pressure gauge shall be marked with the name of the operator, the location of the gauge, the date that it was placed upon the gauge, and the date that it was removed from the gauge prior to its filing.