§43.  Discrimination by purchaser

No common purchaser shall discriminate between like grades and pressures of natural gas, or in favor of its own production or of production in which he may be directly or indirectly interested, either in whole or in part, but for the purpose of pro-rating the natural gas to be marketed, this production shall be treated in like manner as that of any other producer or person, and shall be taken only in the ratable proportion this production bears to the total production available for marketing.