In some small cities or villages and industrial region due to low population , impossibility to cross or other problems , establishment of gas transmission line is very hard and in some cases very expensive which is not economically justifiable In this method gas is transferred to areas by trailer containing compressed natural gas. In fact, cities or villages or industrial zone which are receiving this service owns a local gas transfer pipeline which through a terminal is connected to the cylinders containing compressed natural gas. These cylinders are brought to these areas from their origin station where they are filled with natural gases.
In this method the supplying station is so called Mother and Distribution station is so called Daughter.
In this method, natural gas is filled in CNG cylinders and carried by trailer to areas excluding main gas pipeline where the gas pressure is reduced in Daughter station and distributed to consumers through a local pipeline.