100. NORMAL Each gas utility shall establish a normal pressure at which gas will be supplied to its connection with the customer's facilities.105. VARIATION Gas pressure supplied at the point of delivery shall not drop below one-half of normal pressure or exceed twice the normal pressure as established in Section 100 above.110. VIOLATIONS1. No utility shall be deemed to have violated the preceding paragraph of this rule if it can be shown to the satisfaction of the Commission that the variations occurring in gas pressure were due to unforeseen demand or to temporary conditions beyond the control of the utility.2. No utility shall be deemed to have violated any stipulation of this rule with respect to individual cases if it can be shown to the satisfaction of the Commission that, in any such individual case, the service line or any pipe lines on customer's property are of such size or condition as to render the maintenance of the pressure and pressure variation impracticable.115. TESTING EQUIPMENT Each utility shall maintain on its distribution system in each city in which it supplies gas, at least one recording gas-pressure gauge for each 50 miles of mains or fraction thereof. No utility shall maintain less than two recording gauges, of which one should be portable.120. RECORDS Each utility shall regularly make records with such recording gauges of the pressures in various parts of its distribution system. The charts of records thus obtained shall bear the date and place where the pressure was taken and shall be available for inspection. Miss. Code. tit. 39, pt. 3, subpt. 4, ch. 52