Abstract: With regard to four typical problems existed in the process design ofTrans-Asia Natural Gas Pipeline, the fragility of pipe under lowtemperature, pipeline hydrotest, pressure grade and material selection of valves, waterproof of vertical venting pipe are analyzed. Under low-temperature, cracking of pipe can be prevented by insulating, controlling low-temperature flexibility of material and transforming corresponding codes for the construction of pump station. For the determination of water pressure, the design party provides the information about "pressure strength of field hydrotest and hydrotest duration" to the technical clauses to pipe supplier, and the pipe supplier lists the relevant yard hydrotest indices in bidding contract. For the selection of pressure grade and material of valves, the requirements in the design pressure and temperature are satisfied by applying standard class, special class and enhanced class or rated class. Considering the waterproof design defect in venting vertical pipe, a new design scheme is presented based on international design theory.