S.D. Codified Laws § 34-39-6
All liquid gas meters shall be of a positive displacement type equipped with vapor separator or provided with such other equipment which will positively eliminate all air and vapor from passing through the meter with the liquid gas, and differential pressure regulator. A liquid gas meter, except a meter dispensing at a rate of twenty gallons per minute or less, shall be corrected to sixty degrees Fahrenheit liquid gas temperature and all deliveries of liquid gas through the meter shall be temperature corrected from sixty degrees Fahrenheit to the temperature of the liquid gas at the time and place of delivery and the customer billed accordingly. It is a Class 1 misdemeanor to make wholesale or retail sales to customers from any bulk delivery vehicle unless the bulk delivery vehicle is equipped with and dispenses the liquid petroleum gas through a liquid gas meter. No liquid gas meter may be equipped with a bypass around the liquid gas meter. However, the prohibition of a bypass is not intended to prohibit the use of an equalization line.
SDCL 34-39-6