API 520-2 pdf download Sizing, Selection, and Installation of Pressure-relieving Devices Part II—Installation 6.2 Safe Disposal of Relieving Fluids For a comprehensive source of information about the safe disposal of various relieving fluids, see API 521 [3] . 6.3 Backpressure Limitations and Sizing of Pipe 6.3.1 General When discharge piping is designed, consideration should be given to the combined effect...